mineral
Milky quartz (possibly chalcedony)
Quartz, SiO₂; likely massive or cryptocrystalline quartz
AI-generated identification · may be incorrectWhite to pale bluish translucent, vitreous-to-waxy luster, irregular conchoidal fracture, and no obvious cleavage; Mohs hardness 7, specific gravity about 2.65. The cloudy appearance comes from microscopic fluid inclusions or fine internal fractures.
Identified More mineral →
Explore Milky quartz (possibly chalcedony) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
White to pale bluish translucent, vitreous-to-waxy luster, irregular conchoidal fracture, and no obvious cleavage; Mohs hardness 7, specific gravity about 2.65. The cloudy appearance comes from microscopic fluid inclusions or fine internal fractures.
Formation & geological history
Forms when silica-rich fluids precipitate in cavities, veins, or fractures, commonly in igneous and metamorphic rocks; individual specimens may range from ancient Precambrian to much younger. The orange spot may be iron-oxide staining or an inclusion.
Uses & applications
Used for decorative stone, carvings, abrasives, countertops, and glass manufacture; attractive translucent pieces are collected but are generally inexpensive.
Geological facts
Quartz is one of Earth’s most abundant minerals and crystallizes in the trigonal system, though massive specimens may show no visible crystal faces.
Field identification & locations
Identify by its glassy/waxy appearance, lack of cleavage, conchoidal fracture, and ability to scratch ordinary glass; a steel blade should not scratch it. Common worldwide, especially in hydrothermal veins, pegmatites, and quartz-rich metamorphic rocks.
