Quartz (beads)

Quartz has a Mohs hardness of 7. The beads in the image display a range of colors including white (milky quartz), pale pink (rose quartz), and yellow/golden (possibly citrine or yellow quartz). All exhibit a vitreous (glassy) luster when polished. Its crystal structure is trigonal. Quartz does not have distinct cleavage but exhibits conchoidal fracture.

Quartz is one of the most abundant minerals in the Earth's crust. It forms from the cooling of igneous rocks, crystallization from hydrothermal solutions, and during metamorphic processes. It is also a primary constituent of many sedimentary rocks. The specific varieties shown (white, rose, yellow) form under various conditions, often in pegmatites, hydrothermal veins, or igneous and metamorphic rocks. Its geological age varies widely, from billions of years old to relatively young formations.

Quartz beads are widely used in jewelry making for necklaces, bracelets, and earrings. Due to its hardness and availability, quartz (especially clear varieties) is used in electronics (oscillators, filters), optics, and as an abrasive. Certain colored varieties like amethyst, citrine, and rose quartz are popular gemstones. Milky quartz, rose quartz, and yellow quartz are often shaped into cabochons, carvings, and polished spheres for decorative purposes and metaphysical practices.

Quartz is the second most abundant mineral in Earth's continental crust. Its piezoelectric properties (generating electric charge under mechanical stress) make it essential in electronics. Rose quartz is often associated with love and compassion, while citrine (a yellow-to-orange variety) is linked to prosperity. The variations in color are due to trace impurities; for example, iron causes the pink in rose quartz, and irradiation of aluminum impurities can create the yellow in some quartz.

In the field, raw quartz can be identified by its glassy luster, hardness (it scratches glass), lack of cleavage, and conchoidal fracture. It is ubiquitous and can be found globally in various geological settings, including igneous, metamorphic, and sedimentary rocks. Common locations for gem-quality quartz include Brazil, Uruguay, Madagascar, and the United States (e.g., Arkansas). For polished beads like those pictured, identification relies on color, transparency, and the characteristic glassy appearance. They are often sold alongside other semi-precious gemstone beads.