[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.c47.2 # Minerals and Metals in Ancient India v2.c47.2 Minerals and Metals in Ancient India v2.c47.2 - **Language:** English ### [v2.c47.2](https://indike.org/pramana/ins.science.biswas-1996.v2.c47.2) \*Actinolite\* : Means ray in Greek. Calcium-magnesium-iron amphibole Ca₂ (Mg, Fe)₅ (OH)₂ (Si₄O₁₁)₂. Ca-Mg amphibole is tremolite (white). Due to iron, actinolite is dark-green. Mixture of the two is asbestos (does not contain hardening aluminium). Aluminium makes the structure hard and results in jade family of numerals (hardness 6-7). \*Nephrite\* may be white jade or green due to iron and manganese. The apple-green and emerald green colour of \*jadeite\* is due to the presence of chromium. It could be mauve or light blue also. The black colour of \*chloromelanite\* is due to excess concentration of iron in the structure. \*Smaragdite\* is near actinolite in composition but contains some aluminium. It is thin-foliated and has a light grass-green colour. The word for green is \*smaragdus\* in Latin and \*smaragdos\* in Greek. - [Previous: v2.c46.s6.32](https://indike.org/pramana/ins.science.biswas-1996.v2.c46.s6.32) - [Next: v2.c47.3](https://indike.org/pramana/ins.science.biswas-1996.v2.c47.3) - [Up: v2.c47](https://indike.org/pramana/ins.science.biswas-1996.v2.c47) --- Source: [https://indike.org/pramana/ins.science.biswas-1996.v2.c47.2](https://indike.org/pramana/ins.science.biswas-1996.v2.c47.2) · Pramāṇa