Chalcedony
Incredible stalactitic formation of quartz on black basalt. This specimen is a world class piece of the highest quality, with excellent luster and unique formations. Be sure to check the video! Known to many by it's trade name "Black Chalcedony", this example is of the best quality of this material and not easy to come by. This piece is truly one of a kind, don't let it slip away!
From Jalgaon, India. Shown as recommended on the Small Adjustable Mineral Stand, not included with purchase. Please see the ruler photo for size reference. Please contact us with any questions.. Please contact us with any questions.
Chalcedony is a captivating variety of quartz prized by collectors for its wide array of colors and formations. It is a cryptocrystalline form of silica, composed of fine intergrowths of quartz and sometimes moganite, giving it a smooth, waxy luster. Sometimes the surface can form very small druzy crystal faces, such as seen here with Black Chalcedony, that create a dazzling glitter effect.
Chalcedony can exhibit various hues, including white, blue, gray, yellow, orange, and even shades of pink and green, often influenced by trace impurities. Its translucence and sometimes opaque nature, coupled with its ability to take a high polish, make it a popular choice for gemstone and jewelry enthusiasts. Collectors are drawn to its diverse forms, such as agate, jasper, carnelian, and onyx, each with distinct patterns and colors. With its rich history and aesthetic appeal, chalcedony remains a beloved and versatile addition to any mineral collection.
Chalcedony is primarily comprised of quartz, the most common mineral on earth, which is celebrated for its diverse forms, widespread availability, and captivating beauty. Composed of silicon dioxide (SiO₂), quartz crystallizes in the hexagonal system, often forming six-sided prisms terminated with pyramidal ends. This mineral is remarkably hard, ranking 7 on the Mohs hardness scale, which makes it durable and suitable for various uses. Quartz comes in an array of colors and varieties, including clear prismatic crystals, purple amethyst, smoky quartz, agates, jaspers, and much more.
Collectors are particularly drawn to quartz's ability to form large, well-defined crystals and fascinating inclusions, such as rutile needles or chlorite phantoms. Found in a multitude of geological environments, from igneous and metamorphic rocks to hydrothermal veins, notable quartz localities include Brazil, Madagascar, the United States, and Switzerland. The sheer variety and beauty of quartz, combined with its robust nature, make it an essential and versatile addition to any mineral enthusiast's collection.