Figure 1. These afghanite (2.0 g, left) and haüyne (0.9 g, right) samples are representative of rough material from Badakhshan, Afghanistan, that was purchased in the Peshawar mineral market in 2006–2007. Photo by Robert Weldon.

In April 2007, Farooq Hashmi (Intimate Gems, Jamaica, New York) loaned two parcels of blue rough from Badakhshan, Afghanistan, to GIA for examination. He purchased the parcels in Peshawar, Pakistan. One group was dark blue and sold to him as afghanite, and the other was "turquoise" blue with its identity unknown to the seller (e.g., figure 1). Mr. Hashmi also donated a sample of each color to the RRUFF project (http://rruff.info), and both were analyzed by single-crystal X-ray diffraction and electron microprobe. The dark blue fragment (R070558) was identified as afghanite with the formula (Na_19.10K_2.90)_Σ=22Ca_10.00(Si_24.00Al_24.00)_{Σ =48}O₉₆(S_1.00O₄)₆([OH]_3.21Cl_2.79)_{Σ =6} (OH estimated by difference and charge balance), and the "turquoise" blue sample (R070557) was haüyne with the formula Na_3.00(Ca_0.84Na_0.16)_{Σ =1}(Si_3.05Al_2.95)O₁₂([SO₄]_0.89Cl_0.11)_{Σ =1}.

Gem-quality afghanite is quite rare, although the Winter 2003 Gem News International (GNI) section (pp. 326–327) documented some cabochons from Badakhshan containing conspicuous lazurite inclusions. Haüyne is likewise uncommon in gem quality, and facetable material is principally known from Germany (see, e.g., L. Kiefert and H. A Hänni, "Gem-quality haüyne from the Eifel District, Germany," Fall 2000 Gems & Gemology, pp. 246–253).

Figure 2. Faceted afghanite is extremely rare. These stones from Badakhshan weigh 0.79 and 0.34 ct. Photo by Robert Weldon.

Some of Mr. Hashmi’s rough afghanite was sufficiently large and transparent to facet, so he had two stones cut by John Bradshaw (Coast-to-Coast Rare Stones International, Nashua, New Hampshire): a 0.34 ct emerald cut and a 0.79 ct modified triangular step cut (figure 2). To stabilize the larger stone and improve its transparency, Mr. Bradshaw filled the fractures with an epoxy resin.

Both faceted afghanites were characterized by standard gemological techniques. These samples had intense blue to moderate blue pleochroism, refractive indices of 1.530–1.538 (birefringence 0.008), and SG values of 2.51 (larger stone, determined hydrostatically) and 2.54 (smaller stone; obtained by DiaVision, a noncontact optical measuring device that was used to calculate SG based on the measured weight and calculated volume, when the hydrostatic method failed due to persistent gas bubbles). The stones were inert to long-wave UV radiation, and had an inert to weak red reaction to short-wave UV (except for very weak to moderate yellowish white fluorescence confined to the fractures in both stones). A desk-model spectroscope showed a weak absorption band at approximately 590 nm. Our RI and birefringence values are somewhat higher than the data reported for afghanite in the Winter 2003 GNI entry and by R. V. Gaines et al. (Dana’s New Mineralogy, John Wiley & Sons, New York, 1997, p. 1634). The SG values determined for this report are lower than those in Gaines et al. (1997), but comparable to those in the Winter 2003 GNI entry.

The smaller stone contained parallel breaks (afghanite has one perfect cleavage) and transparent crystals identified as diopside by Raman microspectroscopy. The larger sample had transparent two-phase inclusions that contained a dark solid material as well as colorless prisms; unfortunately, they were too deep in the stone to be identified by Raman analysis. In both stones, however, the dominant internal features were fractures with evidence of enhancement. Although Mr. Bradshaw had only filled the fractures in the larger stone, he indicated that the residue in the untreated stone might be due to the "soaking off" process, in which the epoxy used to attach the stone to the dop stick was dissolved by immersion in methylene chloride.

Polarized ultraviolet-visible-near infrared (UV-Vis-NIR) absorption spectroscopy of both samples showed distinct bands at approximately 370, 590, and 895 nm. These bands are quite similar to those documented in haüyne by Kiefert and Hänni (2000). The band at 590 nm is responsible for the blue color. In both of our samples, energy-dispersive X-ray fluorescence (EDXRF) spectroscopy showed major amounts of Si, Al, Ca, K, S, and Cl, which are expected for afghanite, as well as traces of Sr and Ba.

By coincidence, two faceted examples of haüyne from Badakhshan were seen at GIA in 2006–2007. In August 2006, Brad Payne (The Gem Trader, Grand Rapids, Michigan) submitted a 1.21 ct stone to the GIA Laboratory for an identification report. He had purchased the rough as afghanite, but after cutting the stone he noted properties that were inconsistent for this mineral. The GIA Laboratory recorded the following characteristics: color—greenish blue, with no pleochroism; RI—1.499; optic character—singly refractive; hydrostatic SG—2.44; fluorescence—moderate-to-strong orange to long-wave UV radiation and very weak orange to short-wave UV; and a cutoff at ~450 nm and an absorption band at 600 nm visible with the desk-model spectroscope. These properties are comparable to those reported for haüyne by Kiefert and Hänni (2000), except for the greener color. Microscopic examination revealed cleavage fractures and slightly flattened whitish crystalline inclusions. EDXRF spectroscopy showed major Si, Al, Ca, Na, K, S, and Cl, which are consistent for both haüyne and afghanite. However, the Raman spectrum provided the best match for haüyne.

Then, in early 2007, Dudley Blauwet (Dudley Blauwet Gems, Louisville, Colorado) sent a 0.92 ct oval cut from Badakhshan to GIA for examination. He had obtained the piece of rough in December 2006 in Peshawar; he also purchased similar material there in June 2006 and November 2007. The 0.92 ct oval cut was similar in color to the stone from Mr. Payne, but brighter, and Raman analysis of a fragment from the same piece of rough by Dr. Robert Downs (Department of Geosciences, University of Arizona, Tucson) gave a spectrum that was identical to that of Mr. Hashmi’s haüyne. So far Mr. Blauwet has cut 114 of these haüynes (total weight 16.89 carats), and he noted a particularly good demand for this unusual brightly colored gem in the Japanese market.

David M. Kondo
GIA Laboratory, New York

Brendan M. Laurs

Eric Fritz
Denver, Colorado