Specimen at a glance
| Mineral | Hematite with goethite |
|---|---|
| Chemistry | Fe2O3 |
| Mohs hardness | 5.5–6.5 |
| Crystal system | Trigonal |
| Locality | Graves Mountain, Georgia, USA |
| Form | Raw / rough |
| You receive | The exact specimen pictured |
About this specimen
Graves Mountain in Lincoln County, Georgia is one of the world’s best-known localities for iridescent hematite, sometimes called “rainbow” or “peacock” hematite. The iridescence isn’t a coating or treatment — it comes from an ultra-thin natural oxidation layer on the hematite’s surface that splits light the same way a thin film of oil does on water, producing shifting colors across the metallic gray surface as the angle of light changes.
Hematite is an iron oxide (Fe₂O₃) at Mohs hardness 5–6, and this piece also shows patches of goethite, an iron oxyhydroxide (FeO(OH)) with a slightly softer, more textured, almost bubbly surface that often forms alongside hematite at the same localities. Seeing both minerals together on one specimen is typical of Graves Mountain material and adds visual depth beyond the iridescence alone.
This is the exact piece pictured, with its rainbow sheen and goethite texture catching the light beautifully from multiple angles — a standout for hematite and Georgia locality collectors, and a strong display piece on its own.
Inside Hematite & Goethite
The rainbow sheen here is the same physics as an oil slick — not dye, not coating.
The story: Both minerals are weathering products of iron-bearing rock, and both were major players in the Great Oxidation Event roughly 2.4 billion years ago, when Earth’s oceans first filled with free oxygen and dissolved iron began rusting out of solution on a planetary scale. Where hematite and goethite grow intergrown in thin layers, they can produce the iridescent, rainbow-sheened surface seen on pieces like this one — a thin-film interference effect, the same optics as an oil slick on water.
Why collectors chase it: That metallic rainbow iridescence makes these among the most photogenic specimens in any mineral collection.
Care: Durable, but a real streak test (rubbing on unglazed porcelain) leaves a permanent red-brown mark — don’t test it on your own display tile.
Rainbow hematite: the science
- Hematite always leaves a red-brown streak on unglazed porcelain, even when the crystal itself looks black or silver.
- Graves Mountain, Georgia is a classic locality for iridescent hematite, along with rutile and lazulite.
- The rainbow is thin-film interference, the same effect as color on a soap bubble, not a coating or dye.
Go deeper
Want the full story on rainbow hematite: how it forms, how to identify it, and what makes a great specimen?
Questions about this piece
What is rainbow hematite?
Rainbow hematite is iron oxide whose surface shows iridescent colors. At Graves Mountain, Georgia, thin surface layers on hematite crystals scatter light into rainbow hues.
Where was it found?
This piece comes from Graves Mountain, Georgia, USA. We list a locality whenever it is known, because where a mineral formed is part of its story and its value.
How hard is it, and how should I care for it?
It rates 5.5–6.5 on the Mohs scale. Handle by the edges: skin oils dull the iridescence. Keep dry and dust gently. Do not scrub the surface.
Is this the exact piece I will receive?
Yes. This listing was photographed individually, and you receive the exact piece shown in the photos.
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