Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a> (CC BY 2.0)
trigonalcommonSilicates (Tectosilicates)
Milky Quartz
SiO2
Milky quartz is a common variety of quartz characterized by its cloudy, opaque to translucent white appearance, often forming in massive aggregates or as vein fillings. The image shows milky quartz matrix with distinct purple amethyst crystals growing on it.
Milky Quartz Physical Properties
Mohs Hardness
7Crystal System
trigonalLuster
vitreousStreak Color
whiteCleavage
none (or very poor/indistinct)Fracture
conchoidalSpecific Gravity
2.65Colors
white, off-white, translucent whiteTransparency
translucentType Locality
Diamond Hill, Ashaway Village, Hopkinton, Rhode Island, USAMineral Group
Silicates (Tectosilicates)Uses
industrial (abrasives, ceramics), filler material, ornamental stone (less common for milky variety), collectorAssociated Minerals
amethyst, feldspar, mica, calcite, pyriteRarity
commonGeological Context
Milky quartz forms in a wide range of geological environments, including hydrothermal veins, pegmatites, and igneous and metamorphic rocks. Its milky appearance is often attributed to microscopic fluid inclusions trapped during crystal growth.
