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.
Rose Gold gets its rosy tint by mixing copper with gold. The ratio of gold to copper is usually 3:1, but varying percentages can be used as well, the intensity of the color differs according to the ratio of gold and copper. Jewelry with rose gold plating gives off a quality of elegance and femininity.