[Pramāṇa](https://indike.org/pramana/) › [Studies](https://indike.org/pramana/ins) › [Science, technology and education](https://indike.org/pramana/ins.science) › [Minerals and Metals in Ancient India](https://indike.org/pramana/ins.science.biswas-1996) › v2.c47.73 # Minerals and Metals in Ancient India v2.c47.73 Minerals and Metals in Ancient India v2.c47.73 - **Language:** English ### [v2.c47.73](https://indike.org/pramana/ins.science.biswas-1996.v2.c47.73) \*Gypsum\* : CaSO₄, 2H₂O. Greek \*gypsos\* (= plaster). Hardness 1.5-2.0 Varieties: Crystallized or \*Selenite\* is colourless or transparent. \*Alabaster\* is a massive fine-grained variety, white or delicately shaded. \*Rock gypsum\* may have silica, clay or calcium carbonate as impurities. - [Previous: v2.c47.72](https://indike.org/pramana/ins.science.biswas-1996.v2.c47.72) - [Next: v2.c47.74](https://indike.org/pramana/ins.science.biswas-1996.v2.c47.74) - [Up: v2.c47](https://indike.org/pramana/ins.science.biswas-1996.v2.c47) --- Source: [https://indike.org/pramana/ins.science.biswas-1996.v2.c47.73](https://indike.org/pramana/ins.science.biswas-1996.v2.c47.73) · Pramāṇa