Unakite

Hardness: 6-7 on Mohs scale. Color: Distinctive mottled green (epidote) and pink/red (feldspar, typically orthoclase). Luster: Vitreous to greasy. Crystal structure: Granular, massive. No distinct cleavage planes for the rock itself, but component minerals have cleavage. Specific Gravity: 3.2-3.5.

Unakite is an altered granitic rock, formed when granite undergoes metasomatism, a type of metamorphism where hot hydrothermal fluids replace original minerals. Specifically, plagioclase feldspar in granite is replaced by epidote, resulting in the characteristic green color. The potassium feldspar (orthoclase or microcline) typically remains pink or red. This process usually occurs during regional metamorphism or in hydrothermal alteration zones. Its geological age varies depending on the original granite formation and the subsequent metamorphic event, ranging from Precambrian to more recent eras.

Primarily used as an ornamental stone, for carving, cabochons, beads (as seen in the image), polished slabs, and decorative objects. It's popular in jewelry due to its distinctive color combination. Occasionally used as a building facade material, but its primary uses are in lapidary and decorative arts.

Unakite was first discovered in the Unaka Mountains of North Carolina, United States, from which it derives its name. It is sometimes considered a type of granite, but due to its alteration and the presence of epidote, it is more accurately classified as a metasomatized or epidotized granitic rock. It is often associated with mystical properties, believed to balance emotions and spiritually ground oneself.

In the field, Unakite is easily identified by its unique mottled appearance of pistachio-green epidote and pink to reddish orthoclase feldspar, often with clear or grey quartz. It is commonly found in the United States (North Carolina, Virginia), South Africa, Sierra Leone, China, and Brazil. Collectors look for pieces with a good balance and contrast between the green and pink colors, and minimal black inclusions (which can be quartz or other minor minerals). The rounded, polished beads in the image are a common form of Unakite encountered by collectors and jewelry makers.