• "Herkimer diamonds" quartz, double terminations - gem formation

    Quartz

    Terminations are flat surfaces or faces at the ends of crystals. Crystals with terminations on just one end are called singly terminated. The other end is either attached to a matrix or lacks faces. Crystals with terminations at both ends, like those shown here, are called doubly terminated. Set of 7 "Herkimer diamonds" (quartz). Herkimer Co., New York, USA. © Rob Lavinsky, www.iRocks.com. Used with permission.

    Article: Gem Formation: How are Gemstones Created?

    Credit: www.iRocks.com

    GemstoneQuartz
    Natural or man madeNatural
    OriginUnited States
    Origin detailsHerkimer Co., New York
    Gem StateRough
    ColorColorless
    TransparencyTransparent