Q. Is pyrite stone valuable?

Tumbled pyrite typically costs between $5 and $10. However for famous sites or pyritized ammonites it can reach several hundred. However for famous sites or pyritized ammonites it can go up to the hundreds. Since pyrite is always opaque in crystal form the key criteria in determining its value are the crystal's habit and its size. Since it is a member of the sulfide’s mineral family pyrite is very different from the more frequent phosphates and sulfates. Attractive silicates carbonates phosphates and oxides are the most often collected minerals. Regardless of age pyrite retains its opaque quality and a dazzling metallic sheen. The mineral pyrite (FeS2) is the most prevalent iron sulfide.