Precious stones are the most beautiful and valuable of all the gemstones. Their colors are vibrant, translucent and brilliant. These natural crystals are also durable, but at the same time rare, and they can be used to create both jewelry and accessories.
Marcasite The mineral marcasite, sometimes called white iron pyrite, is iron sulfide (FeS2) with orthorhombic crystal structure. On fresh surfaces it is pale yellow to almost white and has a bright metallic luster. It tarnishes to a yellowish or brownish color and gives a black streak. It is a brittle material that cannot be scratched with a knife. It typically forms under low-temperature highly acidic conditions.