Milky quartz

Hardness 7 Mohs; white to translucent with a vitreous-to-waxy luster and massive, irregular fracture. Trigonal crystal structure; no cleavage, specific gravity about 2.65.

Forms when silica-rich fluids crystallize in veins or cavities, and also occurs in igneous and metamorphic rocks. Quartz is widespread across geological ages; the specimen’s age cannot be determined from the image.

Commonly used for ornamental carving, countertops, aggregate, and silica products; attractive pieces may be used in jewelry or collections.

Its cloudy appearance results from microscopic fluid or gas inclusions that scatter light.

Identify by its glassy sheen, hardness (it can scratch glass), and lack of cleavage; common worldwide in quartz veins and many rock types. The pictured rough white specimen is consistent with milky quartz.