[Pramāṇa](https://indike.org/pramana/) › [Studies](https://indike.org/pramana/ins) › [Science, technology and education](https://indike.org/pramana/ins.science) › [A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century A.D.](https://indike.org/pramana/ins.science.ray-1902) › v1.c13.19 # A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century A.D. v1.c13.19 A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century A.D. v1.c13.19 - **Language:** English ### [v1.c13.19](https://indike.org/pramana/ins.science.ray-1902.v1.c13.19) Iron pyrites \[Fe S₂\] is brass-yellow in colour, and its dimorphous form marcasite is pale bronze-yellow; but there are other pyrite-like minerals which are silvery white; for instance, cobaltite (Co S₂. Co. As₂), smaltite (Co As₂), löllingite (Fe As₂ with S) and leucopyrite (Fe₃ As₄). Iron pyrites roasted in air would give a red residue of Fe₂ O₃. But it seems more likely that the "golden-yellow" variety is copper-pyrite, which has a deep yellow colour and besides which iron-pyrite when freshly fractured would appear almost silvery in colour. In that case the "essence of the appearance of copper" might be the metal itself.¹ - [Previous: v1.c13.18](https://indike.org/pramana/ins.science.ray-1902.v1.c13.18) - [Next: v1.c13.20](https://indike.org/pramana/ins.science.ray-1902.v1.c13.20) - [Up: v1.c13](https://indike.org/pramana/ins.science.ray-1902.v1.c13) --- Source: [https://indike.org/pramana/ins.science.ray-1902.v1.c13.19](https://indike.org/pramana/ins.science.ray-1902.v1.c13.19) · Pramāṇa