Short answer: unakite is a rock, not a mineral. It is granite that hot fluids altered: the plagioclase turned into pistachio-green epidote, while pink orthoclase feldspar and clear to milky quartz stayed. It is named for the Unaka Mountains on the North Carolina and Tennessee border and is also mined in Virginia, South Africa, Brazil and China. Hardness runs about 6 to 7. Mostly green material without pink is properly epidosite.
Why is unakite a rock and not a mineral?
A mineral is one naturally formed compound with a defined chemistry and crystal structure: epidote, orthoclase and quartz are each minerals. A rock is an aggregate of minerals. Geology.com defines unakite as a pink and green metamorphic rock composed of pink orthoclase, green epidote, and colorless to milky quartz. Minerals.net files it under varieties as an ornamental stone formed from green epidote, pink to gray orthoclase or microcline, and quartz.
That has practical consequences. A rock has no single formula, hardness or specific gravity. Each piece varies with the proportions and grain size of its minerals, and two "unakite" beads can differ visibly in color balance. It is the same reason granite counters vary from slab to slab.
The minerals inside it:
| Mineral | Color in unakite | Formula | Mohs hardness | Specific gravity |
|---|---|---|---|---|
| Epidote | Pistachio to olive green | Ca2(Al,Fe)3(SiO4)3(OH) | 6 to 7 | 3.3 to 3.6 |
| Orthoclase feldspar | Salmon to brick pink | KAlSi3O8 | 6 | 2.6 |
| Quartz | Clear, gray or milky | SiO2 | 7 | 2.65 |
Epidote figures are from Minerals.net's epidote entry and orthoclase from Minerals.net's orthoclase entry. Epidote is the heavy one: at an average specific gravity of 3.45 on Webmineral, green-rich unakite feels noticeably denser in the hand than pink-rich pieces.
How does granite become unakite?
Start with granite. Geology.com's granite article describes it as a light-colored igneous rock that forms from the slow crystallization of magma below the surface, made mainly of quartz and feldspar, typically with pink orthoclase grains alongside quartz and dark mica or hornblende. Granites contain two kinds of feldspar: potassium-rich orthoclase and sodium-calcium plagioclase.
Then add hot water. Geology.com explains that unakite forms when granite is altered by hydrothermal fluids, and that during this metamorphism the plagioclase is replaced by epidote, leaving a rock of green epidote, pink orthoclase and clear to milky quartz. Its epidote page puts the same process in other words: less-resistant minerals in the granite are altered to or replaced by epidote, while the orthoclase and quartz remain. Plagioclase carries the calcium and aluminum that epidote needs; orthoclase, which carries potassium instead, does not react and keeps its pink color.
Geology.com adds where this happens: in the deformed rocks of convergent plate boundaries, where deeply formed granites were metamorphosed and later exposed by erosion, and where igneous intrusions supplied the hot fluids. Unakite can also carry minor magnetite, chromite, ilmenite, apatite and zircon, which show as small black specks in some pieces.
Is it metamorphic or igneous?
The protolith (the original rock) is igneous granite, and the change is hydrothermal alteration. Geology.com's unakite article classes the result as metamorphic, while a photo caption on its own epidote page calls unakite an igneous rock. Both labels appear in the literature for that reason. "Altered granite" is the description nobody disputes.
Where is unakite found?
The name is a place name. Geology.com says unakite is named after the Unaka mountain range of western North Carolina and eastern Tennessee, where it was first discovered and described.
Other sources the same article lists:
- Virginia. Many locations in the Blue Ridge province have been mined for construction, architectural and lapidary unakite.
- New Jersey. Unakite is known as the Pompton Granite in a half-square-mile outcrop in the Piedmont, a building stone used in prominent buildings in New Jersey and nearby states.
- South Africa, Sierra Leone, Brazil and China, which supply most tumbled stones and beads on today's market. Geology.com illustrates tumbled and crushed South African unakite.
The stone has a public showcase in Washington. Geology.com notes that its most prominent architectural use might be at the Smithsonian National Museum of Natural History, as trim on the front steps and floor tiles at the south entrance. It has also been crushed for road base and drainage stone, which says a lot about how common it is.
How do you recognize unakite, and what is epidosite?
Real unakite shows three distinct colors in a coarse, granular texture: opaque salmon-pink feldspar, olive to pistachio green epidote, and glassy gray quartz. Under a 10x loupe the grains have sharp edges, and the pink grains often show flat, shiny cleavage faces, since feldspar has two directions of cleavage meeting near right angles.
The common mislabel goes the other way. Geology.com describes epidosite as a rock composed mainly of epidote and quartz, similar to unakite but with little or no pink feldspar, and says many people call it unakite although epidosite is the proper name. Geology.com's epidote page adds that epidosite forms when basalts in sheeted dikes and ophiolites are transformed by hydrothermal activity, a different parent rock from unakite's granite. If a "unakite" piece is solid green, it is probably epidosite.
Watch also for dyed stones and green jaspers sold under the name. Unakite needs no treatment, so a vivid, unnatural pink, or color concentrated in cracks, is a warning. See our jasper guide and the trade names guide for how such names drift.
Is unakite good for jewelry?
It is serviceable for most jewelry, with limits. Geology.com notes that unakite is not seen in fine jewelry but is a common craft and lapidary stone, cut into cabochons, beads, pendants and freeforms. Because epidote rates 6 to 7 and orthoclase 6, the two minerals are close enough in hardness that cutters rarely see severe undercutting, except in very coarse-grained material or very small pieces.
The weakness is wear. The same article warns that orthoclase and epidote are soft enough to show wear in a bracelet or ring, and both have perfect cleavage, so a moderate knock can break a piece. Pendants, earrings and strung beads hold up best.
How do you care for unakite?
Wash with warm water and mild soap and dry it. Keep it apart from quartz-hard stones and metal tools that can scratch the feldspar and epidote, and avoid dropping it on hard floors, where cleavage can split a bead or cabochon. It is stable in light and needs no special storage.
What is unakite associated with in crystal traditions?
In crystal traditions, unakite is associated with balance and patience, a link usually drawn from its mix of green and pink, and with the heart chakra by color. These are cultural associations, not mineral properties.
Choosing unakite
Because unakite is inexpensive, the choice is about appearance rather than investment. Look for a balanced mix of pink and green with fresh, unweathered grains, a smooth polish without pits where soft grains plucked out, and no cracks along the cleavage. Fine-grained material polishes best and suits small beads; coarse material shows its three minerals more dramatically on larger palm stones and spheres.
- Unakite: low-priced pieces that show the pink orthoclase and green epidote mix; use a loupe to pick out quartz grains between them.
- Epidote crystal clusters on matrix: about 5 by 2.5 by 2 inches and 273 g, a chance to see unakite's green mineral as real crystals rather than grains.
- Peach moonstone: a peach-toned feldspar on its own, showing the feldspar family that supplies unakite's pink grains, here with a soft sheen instead.
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Unakite in stock
Frequently asked questions
Is unakite a mineral?
No. Unakite is a rock made of several minerals: pink orthoclase feldspar, green epidote and clear to milky quartz. It forms when hydrothermal fluids alter granite, turning its plagioclase into epidote while the orthoclase and quartz remain.
Where does the name unakite come from?
It is named after the Unaka mountain range on the border of western North Carolina and eastern Tennessee, where the rock was first discovered and described. Similar material is now mined in Virginia, South Africa, Brazil and China.
What is the difference between unakite and epidosite?
Unakite contains pink feldspar along with green epidote and quartz. Epidosite is mostly epidote and quartz with little or no pink feldspar, and it forms from altered basalt rather than granite. Solid green stones sold as unakite are usually epidosite.
How hard is unakite?
Its main minerals rate about 6 for orthoclase, 6 to 7 for epidote and 7 for quartz. That makes unakite fine for pendants and beads, but rings and bracelets will show wear over time, and the feldspar's cleavage can chip with knocks.
Is unakite ever dyed?
Natural unakite does not need treatment, and most pieces are sold untreated. Be wary of unusually vivid pink grains or color pooled in cracks, which suggest dye, and of solid green stones labeled unakite, which are usually epidosite or green jasper.
Sources
- Geology.com, Unakite: https://geology.com/gemstones/unakite/
- Geology.com, Epidote: https://geology.com/minerals/epidote.shtml
- Geology.com, Granite: https://geology.com/rocks/granite.shtml
- Minerals.net, Unakite: https://www.minerals.net/gemstone/unakite_gemstone.aspx
- Minerals.net, The mineral epidote: https://www.minerals.net/mineral/epidote.aspx
- Minerals.net, The mineral orthoclase: https://www.minerals.net/mineral/orthoclase.aspx
- Webmineral, Epidote mineral data: https://webmineral.com/data/Epidote.shtml