Ferrous Sulfide: Iron Filings Heated with Sulphur (Thorpe 1912)

Heat iron filings with sulphur and they combine into ferrous sulfide, a hard black solid. Its main use: acids decompose it into hydrogen sulfide gas. Result: a very hard, metallic-looking black crystalline solid, sp. gr. 4.69, not magnetic, stable in air, melting at a full red heat. Source: Thorpe, Dictionary of Applied Chemistry, vol. 3 (1912), Iron. Not given: proportions, temperature, vessel. Ours: work outdoors, as burning sulphur gives choking fumes. Picture drawn by Youblob.