While most of the material produced is cabochon-grade, a consistent percentage—maybe 20%—is suitable for faceting. Most of the rough shows color zoning, which is often regarded as an unwanted feature but can be very attractive in the hands of skilled and creative gem cutters. This was the case with an award-winning suite recently cut from Boudi amethyst (figure 8). Both cabochon- and facet-grade material can display strong colors, and significant amounts of rough show a deep reddish purple color. The best crystals exhibit purple flashes with a red tinge. Faceting this deeply colored material can reveal strong red overtones; these stones are known in the trade as “Siberian” amethyst (Wise, 2005). Fine stones larger than 20 carats are regularly faceted, but most of the faceting material is in the 5–10 ct range. Cabochon-grade material up to 100 ct is common. To date, we have not seen heat treatment applied to amethyst from Boudi, which is rarely dark enough to warrant it (Götze and Möckel, 2012; figure 9).
While most of the material produced is cabochon-grade, a consistent percentage—maybe 20%—is suitable for faceting. Most of the rough shows color zoning, which is often regarded as an unwanted feature but can be very attractive in the hands of skilled and creative gem cutters. This was the case with an award-winning suite recently cut from Boudi amethyst (figure 8). Both cabochon- and facet-grade material can display strong colors, and significant amounts of rough show a deep reddish purple color. The best crystals exhibit purple flashes with a red tinge. Faceting this deeply colored material can reveal strong red overtones; these stones are known in the trade as “Siberian” amethyst (Wise, 2005). Fine stones larger than 20 carats are regularly faceted, but most of the faceting material is in the 5–10 ct range. Cabochon-grade material up to 100 ct is common. To date, we have not seen heat treatment applied to amethyst from Boudi, which is rarely dark enough to warrant it (Götze and Möckel, 2012; figure 9).
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