Identification guide · Minerals
How to Identify Heliodor
Heliodor is variable in color with a vitreous luster and is opaque. It has a Mohs hardness of 5. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. It is most often confused with Jade, Calcite, and Diopside; the tests below separate them.
Heliodor identification checklist
| Luster | Vitreous | Fresh surfaces shine like glass; a dull surface usually means weathering, so chip or wet a corner. |
|---|---|---|
| Transparency | Opaque | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 5 | A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. |
| Fracture | Uneven to conchoidal | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 2.7 | Ordinary rock-like heft (specific gravity about 2.7), similar to quartz. |
Extra tests for Heliodor
Glass check. Heliodor shares a glassy luster and conchoidal fracture with man-made glass. Glass sits near Mohs 5.5 and often contains round gas bubbles, so a hardness test and a hand lens separate them.
Heliodor look-alikes and how to tell them apart
Both sit near Mohs 5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Heliodor vs Jade →
Heliodor is harder (Mohs 5) than Calcite (Mohs 3), so Heliodor will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Heliodor vs Calcite →
Diopside is harder (Mohs 5.5–6.5) than Heliodor (Mohs 5), so Diopside will scratch Heliodor and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Heliodor vs Diopside →
Feldspar is harder (Mohs 6–6.5) than Heliodor (Mohs 5), so Feldspar will scratch Heliodor and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
Heliodor identification FAQ
How can you tell if a rock is Heliodor?
Check the color (variable), the vitreous luster, a Mohs hardness of 5. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Heliodor?
Heliodor has a Mohs hardness of 5. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
What is the difference between Heliodor and Jade?
Heliodor (Mohs 5, vitreous luster) and Jade (Mohs 5, vitreous luster) look alike, but hardness, streak and heft usually separate them. See the full Heliodor vs Jade comparison for a side-by-side table.
Is Heliodor worth anything?
Entry-level Heliodor specimens sell for around $2, typical collector pieces about $20, and premium examples $150 or more depending on size, quality and locality.
What color is Heliodor?
Heliodor is most often . Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
