| Rayite | |
|---|---|
| General | |
| Category | Plagionite homologous series |
| Formula (repeating unit) | Pb8(Ag,Tl)2Sb8S21 |
| Crystal system | Monoclinic |
| Crystal class | 2/m - Prismatic |
| Unit cell | a = 13.6 Å, b = 11.96 Å c = 24.49 Å; β= 103.94° |
| Identification | |
| Color | Lead-Grey |
| Crystal habit | Tabular |
| Cleavage | None |
| Mohs scale hardness | 2.5 |
| Lustre | Metallic |
| Streak | Lead-Grey |
| Density | 6.13 g/cm3 (Calculated) |
| Birefringence | Weak |
| Pleochroism | Weak |
| Common impurities | Cu |
| References | [1][2][3][4][5] |
Rayite, a monoclinic mineral containing Lead-Silver-Thallium-Antimony, was found during microscopic and electron microprobe study of specimens from the complex, polymetallic sulphide-native metal sulpho-salt paragenesis of Rajpura-Dariba, Rajasthan, India. It is named after Dr. Santosh K. Ray of President College, Calcutta, India. It bears a striking resemblance to owyheeite in terms of its Lead/(Silver,Thallium)/Antimony ratio, yet its structural affinity lies with Semseyite. The average composition is Lead-47.06, Copper-0.03, Silver-4.54, Thallium-2.04, Antimony-27.42, Sulphur-19.59 by wt.% (total 100.68) suggesting an ideal formula of Pb8(Ag,Tl)2Sb8S21, where Ag > Tl. Meneghinite, Owyheeite, and Galena are related minerals.[1]
- ^ a b Basu, K., NS, B., Mookherjee, A., Nn, M., & Ai, T. (1983). Rare Minerals from Rajpura-Dariba, Rajasthan, India. Iv: A New Pb-Ag-Tl-Sb Sulphosalt, Rayite
- ^ Rayite. Webmineral
- ^ Rayite. Mindat.org
- ^ Mozgova, N. N. & Borodaev, Yu. S. (1972): The homologous series semseyite- fülöppite. Zapiski Vsesoyuz. Miner. Obshch., 101, 299-312 (in Russian)
- ^ Wuensch, B. J. (1980): Superstructures In Sulfide Minerals. In: Cowler, J. М., Cohen, J. B., Salamon, M. B. & Wuensch, B. J., Eds., Modulated Struc- Tures 1979. Amer. Init. Phys. Conference Proc., 58, 337-354.