Unakite

A polished/tumbled geological specimen with a distinctive mottled pink-and-green appearance. The pink areas are chiefly potassium feldspar, the dark green areas are epidote, and small gray or translucent zones may be quartz. Typically has a granular crystalline texture, dull to vitreous luster, no obvious cleavage on the polished surface, hardness about 6–7 on the Mohs scale, and specific gravity roughly 2.7–3.2. The specimen appears rounded and polished rather than naturally weathered.

Unakite forms when granite undergoes hydrothermal alteration and metamorphism, commonly replacing some feldspar and other minerals with epidote while leaving pink feldspar and quartz. It is generally associated with ancient crystalline mountain rocks and may form during Paleozoic or older tectonic events, although the exact age depends on the locality. The name comes from the Unaka Mountains of North Carolina and Tennessee, USA.

Commonly used for polished stones, cabochons, beads, carvings, ornamental objects, and lapidary collectibles. It is also sold as a decorative landscaping or display stone. It has little major industrial use compared with ordinary granite, and its jewelry value is primarily ornamental rather than gem-grade.

The strong pink-and-green color contrast is one of the easiest ways to recognize unakite. Despite being widely marketed as a gemstone, it is a rock rather than a single mineral. Some material sold as unakite may be closely related epidote-rich granite or altered granite with variable amounts of quartz and feldspar.

In the field, look for a coarse-grained, interlocking rock with irregular pink feldspar patches mixed with green epidote and gray-white quartz. It is usually opaque and does not show the banding typical of many jaspers or agates. A fresh broken surface should remain granular, while a polished surface has a soft stone luster. Common sources include the Unaka Mountains of North Carolina and Tennessee, Virginia, Brazil, South Africa, and parts of China. Mineral identification tests or thin-section analysis may be needed to distinguish it confidently from similar pink-and-green granites and jaspers.