Lab Notes Gems & Gemology, Fall 2024, Vol. 60, No. 3

Green Haüyne

Nathan Renfro, Maxwell Hain, and Wim Vertriest

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Figure 1. These seven stones (0.24–1.44 ct) ranging in color from yellowish green to bluish green were identified as the rare gem haüyne. Photo by Annie Haynes.
 
Figure 1. These seven stones (0.24–1.44 ct) ranging in color from yellowish green to bluish green were identified as the rare gem haüyne. Photo by Annie Haynes.

The Carlsbad laboratory recently examined a suite of seven yellowish green to bluish green gems ranging in weight from 0.24 to 1.44 ct (figure 1), which were identified as haüyne, a member of the sodalite group. Gem-quality haüyne is most notable for its intense blue color, especially in material of German origin, so the striking green color of these stones was unexpected. However, a deposit of green haüyne was reported from Afghanistan earlier this year (B. Srisataporn et al., “Green haüyne: A rarity among sodalite gems,” Journal of Gemmology, Vol. 39, No. 1, 2024, pp. 13–16).

Figure 2. A large mica cluster was observed in the 1.44 ct green haüyne. Photomicrograph by Nathan Renfro; field of view 1.83 mm. Courtesy of Bill Vance.
 
Figure 2. A large mica cluster was observed in the 1.44 ct green haüyne. Photomicrograph by Nathan Renfro; field of view 1.83 mm. Courtesy of Bill Vance.

Standard gemological testing revealed properties consistent with haüyne, including an average refractive index of 1.50 and a hydrostatic specific gravity of 2.41. The stones also fluoresced orange to long-wave UV and were inert to short-wave UV. Microscopic examination revealed interesting whitish inclusions, which have been previously reported as mica (figure 2). This was confirmed by Raman spectroscopy. No evidence of clarity enhancement was observed in any of the stones examined. Raman spectroscopy further confirmed the identity of the green gems as haüyne.

This suite represents the first green gem-quality haüyne examined by GIA and is an interesting and rare collector stone.

Nathan Renfro is senior manager of colored stone identification, and Maxwell Hain is a staff gemologist, at GIA in Carlsbad, California. Wim Vertriest is manager of field gemology at GIA in Bangkok.