Adamite

Carat weight is secondary to crystal habit and color; even small stones or crystal fans can be valuable when color is intense and presentation is aesthetic. Larger, clean faceted adamites are rare because the rough is fragile, so size does support a premium when combined with vivid color and acceptable clarity.

Color and fluorescence are primary: vivid lemon-yellow to bright yellow-green with good saturation and minimal browning are most desirable. Stones that glow strongly under UV or short-wave light and still look lively in normal lighting sit at the top of the market, while pale, muddy or unevenly colored material trades at a discount.

Collectors prefer transparent to strongly translucent crystals with limited fractures or cleavage breaks, but some inclusions are tolerated given the mineral's natural fragility. Severe internal cracking that dulls the interior or threatens stability significantly reduces value and usually relegates the piece to lower-tier specimen status.

Most adamite is sold as natural crystal clusters; when cut, simple cushions, ovals or shields that protect edges and minimize cleavage risk are preferred over aggressive designs. Precision cutting that preserves as much thickness as possible while avoiding open feathers can add a modest premium, but overall cutting is constrained by the material's low toughness.

Fine adamite comes mainly from classic localities such as the Ojuela Mine in Mexico and Laurion in Greece, with smaller outputs from Chile, Namibia and a handful of other arsenate deposits. Most high-quality material enters the mineral-specimen market rather than the gem trade, so cuttable rough is sporadic and small in volume, and faceted stones remain genuinely scarce.

Demand is driven almost entirely by mineral collectors and a niche of gem enthusiasts interested in fluorescent or unusual species. Because the stone is fragile, little known to the public and difficult to wear safely, mainstream jewelry demand is minimal, which keeps the market specialized but relatively stable.

Recent years have seen steady, modest growth in interest for fine Ojuela Mine pieces and strongly fluorescent specimens, helped by online mineral photography and auctions. Prices for visually outstanding clusters and rare, clean faceted gems have firmed, while lower-grade material remains thinly traded and relatively inexpensive.