Rock & Mineral Encyclopedia

Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.

Orbicular Granite

A rare granitic rock containing concentric, onion-like spheres called orbicules, prized as a striking ornamental stone.

A common coarse-grained intrusive rock like granite but richer in plagioclase than potassium feldspar.

A pegmatitic granite in which quartz and feldspar intergrow to resemble ancient runic or Hebrew script.

A common rock-forming potassium feldspar, the Mohs hardness reference at 6, found in granites and used in ceramics and glassmaking.

An altered granite mottled pink and green from feldspar and epidote, popular as a tough, colorful ornamental rock.

An altered granite of pink feldspar, green epidote and quartz, mottled pink-and-green and popular as a tumbled and carving stone.