Which grey mineral with metallic lustre is used as a source of tin?

Answer 1

From Wikipedia: " Tin is obtained chiefly from the mineral cassiterite, where it occurs as an oxide....Tin's chemical properties fall between those of metals and non-metals, just as the semiconductors silicon and germanium do. Tin has two allotropes at normal pressure and temperature: gray tin and white tin. A third allotrope, called brittle tin, exists at temperatures above 161 °C. Below 13.2 °C, it exists as gray or alpha tin, which has a cubic crystal structure similar to silicon and germanium. Gray tin has no metallic properties at all, is a dull-gray powdery material, and has few uses, other than a few specialized semiconductor applications." although cassiterite ( an oxide) is the most common source of tin, occaisionally tin is sourced from sulfides such as stannite, a grey mineral with a metallic lustre.