Crafted in 14K two-tone white and yellow gold, this Croft & Stern original design features an 11.9 × 4.6 × 4.2 mm bezel set Maw Sit Sit accented by 3=0.06ctw channel set earth-mined princess cut diamonds. Made is size 9 and finished in a bright polish.
Collector’s Note: Maw Sit Sit is one of the rarest green gem materials on earth—found in only one place in the world: the remote jade mining region of Hpakant, in northern Myanmar (Burma). This area sits within the geological collision zone responsible for forming the Himalayan mountain range. The same forces that created the Himalayas produced the extreme pressure and chemistry needed for Maw Sit Sit to exist.
Often mistaken for jade, it is actually a distinct chromium-rich rock containing kosmochlor and other minerals, which gives it that electric, saturated green with striking dark patterns. Because the locality is singular and production is inconsistent, fine-quality Maw Sit Sit is genuinely scarce. When you see it, you’re looking at something that the earth only created once.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K yellow gold, this Croft & Stern original design features a bezel-set Australian Andamooka opal weighing 1.36ct, displaying vibrant blue and green play-of-color. Accented by two prong-set African blue-green color-change garnets totaling 0.27ctw. Finished with a bright polish.
Collector’s Note: Andamooka Opal & African Color-Change Garnet
Andamooka opal and African color-change garnet are a pairing that delivers both spectacle and rarity. Andamooka opal, from South Australia’s arid outback, is known for its vivid play-of-color and unusually low water content—making it more stable and durable than many opals. It produces both crystal and matrix opal, each showing flashes of color that look like captured lightning. On the other side of the spectrum is African color-change garnet, a natural phenomenon where a single gem shifts between two distinct colors depending on the light—often green or teal in daylight and raspberry or violet under warm indoor light. No treatment, no enhancement—just pure geology showing off. Together, these gems combine the fire of opal with the rare optical magic of garnet. One gem plays with color; the other changes it.
Finger size 9.25
Sizable upon request.
Designed by Kurt Genereux
Designed and Manufactured at Croft & Stern Jewelry Designs, Maple Grove, MN.
Crafted in 14K yellow gold, this Croft & Stern original design features a 3.92ct bezel-set Andamooka opal accented by 6=0.12ctw bezel-set earth-mined round brilliant cut diamonds. It is suspended from an adjustable 16-inch/17-inch/18-inch 0.80mm round wheat chain, secured with a lobster clasp, and finished in a bright polish.
Collector’s note: Andamooka opals, mined in South Australia’s arid outback, are renowned not only for their vivid play-of-color and unique patterns but also for their low water content, typically around 3–6%. This makes them more stable and less prone to cracking or crazing compared to opals from wetter regions, allowing them to retain their beauty over time. Producing both crystal opals, with their translucent brilliance, and matrix opals, with intricate earthy patterns, Andamooka opals are highly sought after by collectors and jewelers alike. Their rarity and durability, combined with historical prestige—such as the 203-carat opal presented to Queen Elizabeth II in 1954—cement their status as exceptional gemstones.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 18K white and yellow gold, this Croft & Stern original design features a 1.55ct bezel-set round Nigerian rubellite. The rubellite is accented by 18=0.55ctw prong-set earth-mined round brilliant cut diamonds with milgrain detail. This ring is made in size 7 with a euro shank and finished in a bright polish.
Collector’s Note: Rubellite
Rubellite is the most coveted member of the tourmaline family, recognized by gem collectors for its true, saturated red-to-raspberry color. Not all pink or red tourmaline qualifies—only stones that retain their rich hue under every lighting condition earn the name “rubellite.” Fine rubellite shows depth, intensity, and an almost glowing translucence, with minimal brown or purple influence. Because rubellite naturally forms with internal inclusions, clean material in strong color is genuinely rare.
Designed and crafted at Croft & Stern Jewelry Designs
Maple Grove, MN
Crafted in 14K two-tone gold, this Croft & Stern original design features a 1.88ct bezel-set precision-cut Montana sapphire accented by four bar-set 2mm earth-mined princess-cut diamonds. The yellow gold is finished in a bright polish, and the white gold is finished in a brushed texture. This ring is made in finger size 8¾.
Collector’s Note: Green Montana Sapphire
Montana sapphires have a cult following for good reason—they’re American-mined, traceable, and naturally distinct. This 1.88ct green sapphire shows exactly what makes Montana material special: crisp clarity, an honest, earthy green, and that subtle steely undertone that no other locality replicates. Unlike mass-market sapphires from overseas, Montana stones aren’t produced by the thousands; they’re pulled in small quantities from gravel bars and ancient riverbeds in the rugged American West. Collectors prize them for their rarity, their ethical sourcing, and their unmistakable color palette shaped by iron-rich geology. A green sapphire of this size and quality from Montana is the opposite of manufactured luxury—it’s genuine, uncommon, and worth holding onto.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K white gold, this Croft & Stern original design features 2=1.38ctw German-cut aquamarines, prong set. Accenting the aquamarines are 2=0.03ctw bezel-set earth-mined round brilliant cut diamonds. Secured with lever backs and finished in a bright polish.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Collector’s Note — German Mirror-Cut Elongated Marquise Aquamarine
This aquamarine is cut in an elongated marquise using the German mirror-cut technique — a precision style built on perfectly aligned, highly polished internal planes. These panels act like mirrors, reflecting light back in controlled flashes rather than scattering it.
The elongated shape emphasizes length and clarity, while the mirror cut reveals crisp, architectural reflections.
This one-of-a-kind necklace features a prong-set custom-cut Alexander Kreis quartz weighing 37.80ct, accented by a prong-set round zircon totaling 1.19ct, and 17 round brilliant diamonds totaling 0.41ctw. The pendant is suspended from a seven-strand gold-tone and stainless steel cable necklace measuring 17", secured with a bayonet clasp. Finished with a bright polish.
Collector’s Note: Alexander Kreis–Cut Gem
An Alexander Kreis–cut gem is not factory perfection—it’s artistic intuition. Kreis cuts completely freeform, by hand, without a predetermined pattern. He studies the rough, listens to the material, and lets the gem dictate what it wants to become. No two gems are ever alike. Based in Germany near Idar-Oberstein—the historic heart of European gem cutting—the Kreis family has more than 500 years of continuous gem-cutting tradition, passing down skill and sensitivity to gems through generations. Instead of forcing symmetry or chasing carat weight, Alexander prioritizes optical movement, internal architecture, and the natural personality of the gem. Collectors seek his work because it’s the opposite of mass production: each piece is a conversation between cutter and gem, a one-of-a-kind sculpture in miniature.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern Jewelry Designs, Maple Grove, MN
Crafted in 14K white gold, this Croft & Stern original design features 2=3.35ctw prong-set round Tanzanian “spice” colored zircons accented by 2=0.04ctw prong-set earth-mined round brilliant cut diamonds. These earrings are secured with posts and friction backs and finished in a bright polish.
Collector’s Note: Zircon holds a distinction no other gemstone can claim—it is the oldest known mineral on Earth. Individual zircon crystals discovered in Western Australia have been dated to 4.4 billion years, formed when the planet’s crust was still cooling. Nothing else you can wear on your body predates the continents.
Zircon is scientifically significant because of its chemistry. When zircon forms, it naturally incorporates tiny amounts of uranium, but excludes lead. Over time, the uranium slowly decays into lead at a predictable rate. By measuring that uranium-to-lead ratio, scientists can determine the age of the zircon crystal with remarkable accuracy.
This dating method—uranium-lead (U-Pb) dating—is one of the most reliable ways geologists determine the age of rocks and major events in Earth’s history.
So while zircon dazzles with brilliant light dispersion and rich natural color, its real power is this:
You’re not just wearing a gemstone.
You’re wearing a piece of Earth’s timeline—a mineral used to measure the age of the planet itself.
Designed by Kelly Sternau
Crafted by Croft & Stern Jewelry Designs
Maple Grove, MN
Crafted in 14K white gold, this Croft & Stern original design features a 2.82ct amethyst paired with 1.22ctw of faceted tourmalines. Accenting the design are 12 prong-set earth-mined round brilliant cut diamonds totaling 12=0.34ctw. Suspended from an 18-inch, 1.05mm diamond-cut square wheat chain, secured with a lobster clasp, and finished with a bright polish.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern Jewelry Designs, Maple Grove, MN
Crafted in 14K yellow gold, this Croft & Stern original design features a 1.91ct bezel-set Australian Andamooka opal paired with a 0.29ct bezel-set round lavender spinel. Suspended from a 0.80mm round wheat chain adjustable to 16", 17", or 18", secured with a lobster clasp and finished in a bright polish.
Collector’s note:
Andamooka opals, mined in South Australia’s arid outback, are renowned not only for their vivid play-of-color and unique patterns but also for their low water content, typically around 3–6%. This makes them more stable and less prone to cracking or crazing compared to opals from wetter regions, allowing them to retain their beauty over time. Producing both crystal opals, with their translucent brilliance, and matrix opals, with intricate earthy patterns, Andamooka opals are highly sought after by collectors and jewelers alike. Their rarity and durability, combined with historical prestige—such as the 203-carat opal presented to Queen Elizabeth II in 1954—cement their status as exceptional gemstones.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K yellow gold, this Croft & Stern original design features a 7.52ct semi-bezel set citrine cut by Alexander Kreis. Accented by six 1.3mm prong set earth-mined round brilliant cut diamonds. Suspended from a 5mm wide black silk cord adjustable from 17" to 19". Secured with a lobster clasp and finished with a bright polish.
Collector’s Note: Alexander Kreis–Cut Gem
An Alexander Kreis–cut gem is not factory perfection—it’s artistic intuition. Kreis cuts completely freeform, by hand, without a predetermined pattern. He studies the rough, listens to the material, and lets the gem dictate what it wants to become. No two gems are ever alike. Based in Germany near Idar-Oberstein—the historic heart of European gem cutting—the Kreis family has more than 500 years of continuous gem-cutting tradition, passing down skill and sensitivity to gems through generations. Instead of forcing symmetry or chasing carat weight, Alexander prioritizes optical movement, internal architecture, and the natural personality of the gem. Collectors seek his work because it’s the opposite of mass production: each piece is a conversation between cutter and gem, a one-of-a-kind sculpture in miniature.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in platinum, this Croft & Stern original design features a 3.10ct prong set Santa Maria aquamarine accented by 6=0.21ctw prong set round aquamarines, 36=0.36ctw prong set earth-mined round brilliant cut diamonds, and 2=0.63ctw bar set earth-mined radiant cut diamonds graded H color and VS clarity. Finished in a bright polish.
Collector’s Note: Santa Maria Aquamarine
“Santa Maria” aquamarine refers to a specific and highly coveted color—a deep, saturated blue originally found in the Santa Maria de Itabira mine in Brazil. Most aquamarine leans pale, but true Santa Maria material carries an uncommon intensity: a clean, pure blue without the washed-out look. Because the original mine produced limited quantities and is now largely depleted, the name has become shorthand among collectors for that rare, vibrant shade. Today, even stones from Mozambique or Madagascar that match the depth of color are described as “Santa Maria–type,” but the benchmark remains the original Brazilian material.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K white gold, this Croft & Stern original design features 3=3.61ctw bezel-set emerald-cut pink spinels accented by 1=0.05ct bezel-set earth-mined princess-cut diamond and 3=0.03ctw prong-set earth-mined round brilliant cut diamonds. This ring is made in finger size 6½ and finished in a bright polish.
Collector’s Note: Deep Pink Spinel
Deep pink spinel is one of the most coveted hues in the spinel family—a saturated, vivid magenta-pink that rivals the finest hot pink sapphire without the treatments or marketing hype. Unlike sapphire, spinel is almost never heat-treated or enhanced, so what you see is the gem’s natural color, untouched and honest. Fine deep pink spinel comes from limited deposits in Myanmar, Sri Lanka, and Tanzania, and once it's mined, that’s it—nature doesn’t make more. Collectors prize this gem for its crisp brilliance, exceptional clarity, and the way it holds color in every lighting condition.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K yellow gold, this Mark Lauer original features a 12×7mm wave-carved amethyst. Accented by 3 prong-set earth-mined round brilliant cut diamonds totaling 3=0.04ctw. Suspended from an 18" 0.95mm wheat chain and finished with a bright polish.
Designed by Mark Lauer
Collector’s Note: Munsteiner-Cut Amethyst
A Munsteiner-cut amethyst isn’t just a gemstone—it’s a piece of contemporary lapidary art. The Munsteiner family (Bernd and later Tom Munsteiner) pioneered “fantasy cuts,” where the focus isn’t just the gem’s shape, but the sculpture within it. Instead of a standard faceting pattern, the stone is carved with precision grooves, angular internal reflections, and architectural geometry that manipulate light in ways ordinary cutting never achieves. Every facet is intentional, every line engineered to redirect light back through the stone like a prism. Collectors seek these pieces because they’re scarce, entirely hand-finished, and instantly recognizable. When you own a Munsteiner cut, you’re not just buying an amethyst—you’re acquiring work from one of the most influential lapidary artists of the last century, where the gem itself becomes the medium and the light becomes the art.
Crafted in 14K white gold, this Croft & Stern original design features 2=3.56ctw prong-set baguette-cut morganites. Accenting the design are 2=0.59ctw prong-set trillion-cut apatites and 2=0.68ctw prong-set pear-shaped purple sapphires. These earrings are secured with posts and friction backs and finished in a bright polish.
Designed by Kelly Sternau
Manufactured at Croft & Stern Jewelry Designs, Maple Grove, MN
Collector’s Note: Apatite
Apatite is one of those under-sung beauties that rewards anyone who gives it a second look. Known for its vivid, almost electric color range—especially the neon blues and greens from Madagascar, its name comes from the Greek apatáō, meaning “to deceive,” because it masquerades so convincingly as other gems. In reality, apatite stands confidently on its own: vibrant, luminous, and instantly recognizable once you’ve fallen for it.
Because apatite sits softer on the hardness scale, it’s best suited for pendants, earrings, and occasional-wear rings, where its color can shine without heavy abrasion. For collectors, its appeal is the purity of its hues—crystal-clear blues that look lit from within—and the fact that fine specimens are still relatively uncommon in jewelry stores.
Crafted in 14K white gold, this Croft & Stern original design features a prong set fantasy cut amethyst weighing 4.30dwt. The center gem is accented by two prong set Cadillac-cut peridot totaling 2=1.97ctw, and two bezel set earth-mined round brilliant cut diamonds totaling 2=0.03ctw.
Made in finger size 8 and finished with a bright polish.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern Jewelry Designs in Maple Grove, MN
Collector’s Note
This piece is built around a fantasy-cut amethyst, sculpted with a reverse V-cut design — a technique that carves the pavilion from behind to manipulate how light travels through the gem. Instead of relying on traditional flat facets, the cutter creates architectural channels that bend and break light, producing internal reflections that feel almost three-dimensional. The structure pulls color into sharp, geometric flashes, giving the amethyst depth and movement beyond what a standard cut could offer.
Flanking the center are a pair of Cadillac-cut peridots — an angular, elongated shape that was originally developed for fine diamond work. Their crisp, tapered geometry complements the amethyst’s internal sculpture. Together, the three stones form a composition where the cutting style is as compelling as the gemstones themselves.
Crafted in 14K white gold, this Croft & Stern original design features an 8.23ct custom-cut amethyst by Ryan Anderson. Accenting the amethyst are 10=0.12ctw earth-mined round brilliant cut diamonds. This ring is made in finger size 7¾ and finished in a bright polish.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 18K white gold and 14K yellow gold, this Croft & Stern original design features a 9.17ct bezel-set Andamooka opal cut by Paul Christiansen. Accented by a bezel-set 1.47ct round Brazilian chrysoberyl. Suspended from a gold-tone and stainless steel 7-strand collar, 20" length, secured with a bayonet clasp. Finished with a bright polish.
Collector’s note:
Andamooka Opal: Andamooka opals, mined in South Australia’s arid outback, are renowned not only for their vivid play-of-color and unique patterns but also for their low water content, typically around 3–6%. This makes them more stable and less prone to cracking or crazing compared to opals from wetter regions, allowing them to retain their beauty over time. Producing both crystal opals, with their translucent brilliance, and matrix opals, with intricate earthy patterns, Andamooka opals are highly sought after by collectors and jewelers alike. Their rarity and durability, combined with historical prestige—such as the 203-carat opal presented to Queen Elizabeth II in 1954—cement their status as exceptional gemstones.
Chrysoberyl: Chrysoberyl is one of those gemstones serious collectors pay attention to—quietly rare, historically respected, and completely misunderstood by most casual buyers. Long before modern gem fads, chrysoberyl was prized for its hardness (8.5 on the Mohs scale—just under sapphire) and its unmistakable presence in three distinct varieties: traditional yellow-green chrysoberyl, the luminous cat’s-eye, and the elusive color-changing Alexandrite.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern Jewelry Designs, Maple Grove, MN
Crafted in 14K yellow gold, this Croft & Stern original design features 2=3.08ctw bar-set scissor-cut zircons accented by 3=0.10ctw bezel-set earth-mined princess-cut diamonds, 1=0.01ct bar-set earth-mined baguette-cut diamond, and 2=0.10ctw bar-set earth-mined round brilliant cut diamonds. It is suspended from an adjustable 16-inch/17-inch/18-inch 0.80mm round wheat chain, secured with a lobster clasp, and finished in a bright polish.
Collector’s Note: Zircon
Zircon holds the title of Earth’s oldest known mineral, with crystals dated to 4.4 billion years. What makes it scientifically important is its ability to trap tiny amounts of uranium when it forms—then naturally convert that uranium into lead over time. That predictable decay allows scientists to determine ages of ancient rocks using uranium-lead dating, one of the most accurate geologic dating methods in existence. Beyond the lab, zircon delivers exceptional brilliance and fire, often exceeding that of diamond. Whether colorless, blue, or in its rarer warm tones, zircon is an authentic natural gem with history, depth, and light—proof that age can be dazzling.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K yellow gold, this Croft & Stern original design features a flush-set 1.18ct cognac round brilliant cut diamond paired with 2=0.09ctw flush-set earth-mined round brilliant cut diamonds. Made in finger size 9.5 and finished with a bright polish.
Designed by Kelly Sternau
Manufactured at Croft & Stern Jewelry Designs, Maple Grove, MN.
Designed in-house by Kelly Sternau, these one-of-a-kind earrings feature asscher-cut gray spinel set in 14k white gold with rare, kite-shaped slabs of maw sit sit suspended below. Maw sit sit comes from northern Myanmar’s “Jade Tract” in Kachin State, around the village of Maw Sit Sit/Tawmaw in the foothills of the Himalayas. The gem is prized for its unique patterns and rarity. The earrings measure 1.5" total length, with a 3/4" drop from the post, and are finished with secure friction posts and backs. A collector’s piece with a bold, modern edge.
Collector’s Note: Maw Sit Sit & Gray Spinel
Maw Sit Sit and gray spinel make an unexpected, refined pairing—ancient geology meets modern minimalism. Maw Sit Sit is found in only one place on Earth: the Hpakant region of northern Myanmar, within the same geological belt formed by the forces that built the Himalayas. Its vivid chrome-rich green and graphic patterning are completely natural—no dyes, no treatments. Gray spinel, on the other hand, is the connoisseur’s gemstone: cool, smoky, and naturally sophisticated, never heat-treated or enhanced. Where Maw Sit Sit shows bold color and origin-specific rarity, gray spinel brings understated brilliance and clean elegance. Together they strike a balance—one gem full of character and history, the other effortlessly modern and timeless.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K yellow gold, this Croft & Stern original design features a 21 x 14 mm bar set Australian Andamooka opal cut by Paul Christianson, known for its durability and low water content. The opal is accented by 3=0.04ctw prong set earth-mined round brilliant cut diamonds. Finished in a bright polish.
Collector’s note: Andamooka opals, mined in South Australia’s arid outback, are renowned not only for their vivid play-of-color and unique patterns but also for their low water content, typically around 3–6%. This makes them more stable and less prone to cracking or crazing compared to opals from wetter regions, allowing them to retain their beauty over time. Producing both crystal opals, with their translucent brilliance, and matrix opals, with intricate earthy patterns, Andamooka opals are highly sought after by collectors and jewelers alike. Their rarity and durability, combined with historical prestige—such as the 203-carat opal presented to Queen Elizabeth II in 1954—cement their status as exceptional gemstones.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K two-tone gold, this Croft & Stern original design features a 1.85ct semi bezel-set no-heat Madagascar sapphire accented by six bar-set 2mm earth-mined princess-cut diamonds. This ring is made in finger size 8½ and finished in a bright polish.
Collector’s Note: Unheated Madagascar Sapphire
Unheated Madagascar sapphire is a true collector’s find—unaltered, untouched, and exactly as nature formed it. While the majority of sapphires on the market are heat-treated to improve color and clarity, unheated stones represent the top tier: rare, sought after, and increasingly difficult to source. Madagascar is known for producing sapphires with exceptional saturation and a pure, balanced blue that rivals historic Kashmir stones without the price tag. When a sapphire is certified “no heat,” it means its color and internal structure were compelling enough to leave completely natural—no enhancement needed. In a market flooded with treated stones, an unheated sapphire isn’t just a gem; it’s evidence of geological perfection.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K white gold, this Croft & Stern original design features a 14.25ct bezel-set Australian Andamooka opal. Accenting the opal is a prong set 2.04ct round peridot and 4=0.08ctw prong set earth-mined round brilliant cut diamonds. Suspended from a black multi-strand stainless steel cable necklace (seven 0.50mm strands), 18" length, secured with a bayonet clasp and finished in a bright polish.
Collector’s note:
Andamooka opals, mined in South Australia’s arid outback, are renowned not only for their vivid play-of-color and unique patterns but also for their low water content, typically around 3–6%. This makes them more stable and less prone to cracking or crazing compared to opals from wetter regions, allowing them to retain their beauty over time. Producing both crystal opals, with their translucent brilliance, and matrix opals, with intricate earthy patterns, Andamooka opals are highly sought after by collectors and jewelers alike. Their rarity and durability, combined with historical prestige—such as the 203-carat opal presented to Queen Elizabeth II in 1954—cement their status as exceptional gemstones.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K white gold, this Croft & Stern original design features 2=15.93ctw prong-set palm root drops accented by 2=1.78ctw prong-set cushion checker-top black spinels and 2=0.07ctw prong-set earth-mined round brilliant cut diamonds. These earrings are secured with posts and friction backs and finished in a bright polish.
Collector’s Note: Black Spinel & Agatized Palm Root (Indonesia)
Black spinel paired with agatized palm root is a study in natural contrast—refined elegance meets ancient earth. Black spinel is a natural, untreated gem with a crisp, mirror-like polish and a sharper sparkle than onyx or jet. It’s durable, sleek, and never dyed or enhanced. Agatized palm root, sourced from Indonesia, began as prehistoric palm wood that slowly transformed over millions of years as silica-rich groundwater replaced the organic structure with agate. What remains is a fossil turned gemstone—patterns of branching root systems frozen in time. Together, these two materials create a combination that is bold without being loud: modern black brilliance against a one-of-a-kind natural pattern that literally tells the story of ancient earth.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K white and yellow gold, this Croft & Stern original design features a 1.27ct semi-bezel set modified cushion-cut blue spinel. Accenting the spinel are 6=0.06ctw prong-set earth-mined round brilliant cut diamonds. This ring is made in finger size 9½ and finished in a bright polish.
Designed by Kurt Genereux
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Collector’s Note
Blue spinel is one of the few gemstones that doesn’t need enhancement to be beautiful. The color is natural — no heat, no diffusion, no coating. This 1.27ct spinel draws its steely blue tone from trace iron, not cobalt, and it is not lab-grown spinel like the synthetic material used in class rings and souvenir jewelry.
Natural blue spinel is scarce because the conditions required to form it are uncommon. Crystals are typically small, and clean material with good color is even harder to find. Spinel’s crystal structure gives it a crisp, sharp brilliance that diamonds can’t imitate. It’s tough enough for everyday wear and rare enough that most people have never actually seen one in person. Collectors appreciate blue spinel because it offers honest color — no enhancements, no marketing gimmicks. Just a well-cut gem with depth and clarity, meant to be worn.
Crafted in 18K white gold and 14K yellow gold, this Croft & Stern original design features a 9.17ct bezel-set Andamooka opal cut by Paul Christiansen. Accented by a bezel-set 1.47ct round Brazilian chrysoberyl. Suspended from a gold-tone and stainless steel 7-strand collar, 20" length, secured with a bayonet clasp. Finished with a bright polish.
Collector’s note:
Andamooka Opal: Andamooka opals, mined in South Australia’s arid outback, are renowned not only for their vivid play-of-color and unique patterns but also for their low water content, typically around 3–6%. This makes them more stable and less prone to cracking or crazing compared to opals from wetter regions, allowing them to retain their beauty over time. Producing both crystal opals, with their translucent brilliance, and matrix opals, with intricate earthy patterns, Andamooka opals are highly sought after by collectors and jewelers alike. Their rarity and durability, combined with historical prestige—such as the 203-carat opal presented to Queen Elizabeth II in 1954—cement their status as exceptional gemstones.
Chrysoberyl: Chrysoberyl is one of those gemstones serious collectors pay attention to—quietly rare, historically respected, and completely misunderstood by most casual buyers. Long before modern gem fads, chrysoberyl was prized for its hardness (8.5 on the Mohs scale—just under sapphire) and its unmistakable presence in three distinct varieties: traditional yellow-green chrysoberyl, the luminous cat’s-eye, and the elusive color-changing Alexandrite.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern Jewelry Designs, Maple Grove, MN
One-of-a-kind earrings handcrafted in 14k white gold by designer Kelly Sternau, featuring a perfectly matched pair of antique cushion-cut lavender spinels from Myanmar, weighing a total of 2.80ct. These rare gems display the soft violet hues that make lavender spinel so unusual and collectible, especially in well-matched pairs of this size. Each is complemented by 3mm round lavender spinel accents and framed with six round brilliant-cut, earth-mined diamonds totaling 0.12ctw, all set within an elegant leaf-and-vine dangle design. Finished with secure friction posts and backs, these earrings balance fine craftsmanship with the rarity of Burmese lavender spinel—a true collector’s piece. These earrings gracefully dangle at a total length of 1” and have friction style posts and backs.
Collector’s Note: The Mogok region, historically known as the "Valley of Rubies," is famed for producing spinels with remarkable clarity and vibrant hues. Lavender spinels—soft, pastel purple in tone—are exceptionally rare, and matched pairs exceeding 2.5 carats are even more scarce. This particular pair, with their symmetrical cut and consistent coloration, exemplifies the finest Burmese lavender spinels. They represent a truly exceptional find for discerning collectors and connoisseurs, offering both rarity and timeless beauty in the world of fine gemstones.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K white and yellow gold, this Croft & Stern original design features a 2.30ct bezel-set Alexander Kreis–cut aquamarine accented by 13=0.20ctw channel- and prong-set earth-mined round brilliant cut diamonds. Made in finger size 8.75 and finished with a bright polish.
Collector’s Note: Alexander Kreis–Cut Gem
An Alexander Kreis–cut gem is not factory perfection—it’s artistic intuition. Kreis cuts completely freeform, by hand, without a predetermined pattern. He studies the rough, listens to the material, and lets the gem dictate what it wants to become. No two gems are ever alike. Based in Germany near Idar-Oberstein—the historic heart of European gem cutting—the Kreis family has more than 500 years of continuous gem-cutting tradition, passing down skill and sensitivity to gems through generations. Instead of forcing symmetry or chasing carat weight, Alexander prioritizes optical movement, internal architecture, and the natural personality of the gem. Collectors seek his work because it’s the opposite of mass production: each piece is a conversation between cutter and gem, a one-of-a-kind sculpture in miniature.
Designed by Kelly Sternau
Manufactured at Croft & Stern Jewelry Designs, Maple Grove, MN
Crafted in 14K white gold, this Croft & Stern original design features a 4.99ct prong-set fantasy-cut sky blue topaz cut by Alexander Kreis. Accenting the topaz are 15=0.24ctw prong-set earth-mined round brilliant cut diamonds. This ring is made in finger size 7 and finished in a bright polish.
Collector’s Note: Alexander Kreis-Cut Gem
When a gemstone is cut by Alexander Kreis, you’re not just buying a stone—you’re acquiring precision engineering and artistic intention. Known for his sculptural faceting and bold geometry, Kreis approaches cutting with a designer’s eye and a technician’s discipline. His work captures and directs light in a controlled, architectural way—no random sparkle, just clean, deliberate reflections that highlight the stone’s natural color and depth. Kreis cuts aren’t mass-produced; they’re individually evaluated and executed to suit the specific rough, which means each gem is effectively one-of-a-kind. Collectors pursue his pieces because they represent the highest tier of modern faceting: artistry, technical mastery, and the kind of refinement that survives every trend.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K white and yellow gold, this Croft & Stern original design features an 11.47ct prong-set fantasy-cut ametrine. Accenting the ametrine are 5=0.15ctw bar-set earth-mined round brilliant cut diamonds. Suspended from a 2.0mm black silica cord measuring 17 inches in length, secured with a bayonet clasp and finished in a bright polish.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Collector’s Note — Ametrine
Ametrine is rare by nature — a single quartz crystal showing both amethyst (purple) and citrine (gold) in one uninterrupted growth. The color zoning isn’t painted in; it forms underground when iron in the crystal is exposed to different temperatures and oxidation states during growth. Only one primary deposit in the world consistently produces natural ametrine of collectible quality: the Anahí Mine in Bolivia, a deposit that traces back to the 1600s.
This piece pushes the material farther than standard faceting. Instead of cutting flat, predictable facets, the lapidary used concave faceting paired with half-sphere carving from behind, creating the illusion of suspended water droplets inside the gem. The precision of the carving controls how light enters and disperses within the crystal, causing reflections to ripple and break like light moving through liquid.
Crafted in 18K yellow gold and 14K white gold, this Croft & Stern original design features a 7.33ct prong- and semi bezel-set Alexander Kreiss cut quartz accented by 8=0.43ctw prong-set earth-mined round brilliant cut diamonds. This ring is made in finger size 8½ and finished in a bright polish.
Collector’s Note: Alexander Kreis–Cut Gem
An Alexander Kreis–cut gem is not factory perfection—it’s artistic intuition. Kreis cuts completely freeform, by hand, without a predetermined pattern. He studies the rough, listens to the material, and lets the gem dictate what it wants to become. No two gems are ever alike. Based in Germany near Idar-Oberstein—the historic heart of European gem cutting—the Kreis family has more than 500 years of continuous gem-cutting tradition, passing down skill and sensitivity to gems through generations. Instead of forcing symmetry or chasing carat weight, Alexander prioritizes optical movement, internal architecture, and the natural personality of the gem. Collectors seek his work because it’s the opposite of mass production: each piece is a conversation between cutter and gem, a one-of-a-kind sculpture in miniature.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN
Crafted in 14K white gold, this Croft & Stern original design features 2=2.94ctw prong-set Asscher-cut blue zircons and 2=1.63ctw prong-set emerald-cut gray spinels accented by 2=0.02ctw prong-set earth-mined round brilliant cut diamonds. These earrings are secured with posts and friction backs and finished in a bright polish.
Collector’s Note: Blue Zircon & Gray Spinel
Blue zircon and gray spinel are a collector’s pairing that proves sophistication doesn’t need flash. Blue zircon is the oldest known mineral on Earth—dated to 4.4 billion years—and is used in uranium-lead dating to measure the age of the planet. Its brilliance is unmatched, with fire that rivals diamond and a saturated, Caribbean-blue color that occurs naturally (heat brings out its intensity but doesn’t change its identity). Gray spinel, by contrast, is the collector’s insider gem—rare, untreated, and naturally elegant with steely undertones that shift subtly in different lighting. Together, they balance history and modern edge: zircon brings ancient light; spinel brings refined minimalism.
Designed by Kelly Sternau
Designed and Manufactured at Croft & Stern in Maple Grove, MN