Wyoming Nephrite Jade JP Jutras, Cara Williams, Bear Williams, and Lanny Ream
Journal of Gemmology –
Reproduced by permission –
In 2022, a new occurrence of exceptionally pure nephrite jade from central Wyoming, USA, became available to the trade. This nephrite has an unusually fine-grained texture and a uniform medium-to-dark ‘olive’-green body colour. The material’s fine texture results in a highly vitreous lustre (e.g. Figure 1), rather than the more common waxy lustre typically displayed by nephrite jade.
made from Wyoming Sky Zone jade. The strands are resting on a partially polished rough sample of this nephrite.
Photo by J.-P. Jutras.
It is being extracted from a newly recognised in situ occurrence with significant potential. By comparison, past nephrite production in Wyoming has been unreliable and inconsistent, and derived mainly from secondary deposits that are now mostly depleted. Sinkankas (1959) considered Wyoming jade “to be some of the finest nephrite in the world.”
Figure 2: The extent of the main historical nephrite fields (shaded area, after Sutherland 2023) is shown within the state of Wyoming. The Sky Zone occurrence is located in the north-central part of this area. Modified from map of North America provided by Wikimedia Commons.
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Gem-A Press Release
The Gemmological Association of Great Britain (Gem-A) has just released their latest issue of its academic publication, The Journal of Gemmology (Volume 39, No. 1, 2024), featuring silicified coral (a form of fossilization).
Released digitally on 2 April, this issue contains news and research from the international gemmological community, including an article focusing on the mineralogy and colour genesis of silicified coral from Indonesia.
Additional feature articles include an examination of the characteristics and primary hydrothermal origin of nephrite jade from the Sky Zone in Wyoming, USA
And more.
Editor-in-chief Brendan Laurs FGA says: “Most of the articles in this issue focus on some interesting opaque-to-translucent gem materials. The Indonesian silicified coral is widely available on the market, as shown by its prominence at this year’s Tucson gem and mineral shows. The Wyoming nephrite is coming from a new primary deposit and is notable for its very fine-grained texture that enables a high polish lustre.”
In addition to the feature articles, each issue of The Journal of Gemmology contains a Gem Notes section, providing brief reports on diverse items of gemmological interest from around the world. In this issue, among the many items covered are a near-colourless HPHT-grown diamond with natural-appearing blue fluorescence, two new gem materials—yellow-to-orange sodalite and green haüyne—from Badakhshan, Afghanistan, an exceptional carved ‘enhydro’ chalcedony, and the identification of two types of treated and processed amber.
Gem-A CEO Alan Hart FGA adds: “We are thrilled to present another informative and insightful issue of The Journal of Gemmology for Spring 2024. I was especially taken by the cover of this issue, which perfectly highlights the colours and patterns of silicified coral hailing from Indonesia. Our international community of gemmology professionals really values ongoing learning and development, which is why The Journal continues to be such a vital resource for Gem-A Members. Staying abreast of international research and discoveries ensures Gem-A Members are at the forefront of our ever-evolving trade.”
Issues published in the past two years are accessible to Gem-A Members nationally and internationally. Previous issues are freely available to anyone via The Journal’s online archive. A cumulative index covering all issues from 1947 to 2023 and bibliographies covering specific subjects can also be freely downloaded from The Journal’s website.
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