John Cancalosi / Pyrite on Talc. Pyrite (FeS2, iron sulfide) is popularly known as 'fool's gold', formerly used in the production of sulfuric acid. Talc is easily distinguishable by its extreme softness, used in lubri...

John Cancalosi / Talc (hydrated magnesium silicate), easily distinguishable by its extreme softness. Used in lubricants, leather dressings and toiletries. Carlton Talc Mine, Chester, Vermont, USA