We found a pocket of these amazing stones this year at Graves Mountain in Georgia. Iridescent hematite from Graves Mountain displays a metallic luster with vivid rainbow-like colors that shimmer across the surface of the otherwise dark, metallic iron oxide. These colors can include brilliant flashes of blue, green, purple, gold, and magenta, created by a thin film interference effect on the mineral’s surface—similar to what you might see in oil slicks or soap bubbles.

The iridescence often occurs on botryoidal (rounded, bubbly) or tabular crystal surfaces, enhancing the visual depth and complexity of the specimen. The base hematite is usually a deep steel-gray to nearly black, and the rainbow effect contrasts strikingly against it.