Brooch VINTAGE Marcasite; Excellent Condition; No Missing Stones Vintage

Gorgeous Marcasite Vintage Pin/Brooch as identified by ROCK IDENTIFIER. Sophisticated design. Great for accenting hats, coats, and scarves. Invest in Style, Invest in VINTAGE! Marcasite in today's market can be found in antique jewelry stores in pins and other adornments. It wasn't always a desirably accessory, though, and was first famous as a source for sulfur. Chemically, it is identical to pyrite; however, they differ structurally due to differences in development processes. Marcasite can be formed as both a primary or a secondary mineral. It typically forms under low-temperature highly acidic conditions. It occurs in sedimentary rocks (shales, limestones and low grade coals) as well as in low temperature hydrothermal veins. Commonly associated minerals include pyrite, pyrrhotite, galena, sphalerite, fluorite, dolomite, and calcite. As a primary mineral it forms nodules, concretions, and crystals in a variety of sedimentary rock, such as in the chalk layers found on both sides of the English Channel at Dover, Kent, England, and at Cap Blanc Nez, Pas de Calais, France, where it forms as sharp individual crystals and crystal groups, and nodules. As a secondary mineral it forms by chemical alteration of a primary mineral such as pyrrhotite or chalcopyrite.