Identification guide · Silicate Minerals
How to Identify Lazurite
Lazurite is usually blue, deep blue, and azure blue with a vitreous luster and is translucent. It has a Mohs hardness of 5.25. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Its streak is light blue. It is most often confused with Lapis Lazuli, Diopside, and Sodalite; the tests below separate them.
Lazurite identification checklist
| Color | Blue, Deep blue, Azure blue, Violet blue | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Vitreous | Fresh surfaces shine like glass; a dull surface usually means weathering, so chip or wet a corner. |
| Transparency | Translucent | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 5.25 | A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. |
| Streak | Light blue | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | Imperfect | |
| Fracture | Uneven to conchoidal | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 2.4 | Ordinary rock-like heft (specific gravity about 2.4), similar to quartz. |
| Crystal system | Cubic |
Extra tests for Lazurite
Glass check. Lazurite 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.
Lazurite look-alikes and how to tell them apart
Both sit near Mohs 5.25, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Lazurite vs Lapis Lazuli →
Both sit near Mohs 5.25, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Lazurite vs Diopside →
Both sit near Mohs 5.25, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Lazurite vs Sodalite →
Jadeite is harder (Mohs 6.75) than Lazurite (Mohs 5.25), so Jadeite will scratch Lazurite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
Field tips
- Look for an intense azure-blue mineral occurring in white marble, often alongside brassy pyrite grains.
- Lazurite leaves a pale blue streak and is moderately hard, scratching glass with difficulty.
- Distinguish it from lazulite by its softer feel and marble host, and from azurite by its lack of reaction to acid.
Lazurite identification FAQ
How can you tell if a rock is Lazurite?
Check the color (blue, deep blue, azure blue, and violet blue), the vitreous luster, a Mohs hardness of 5.25 and a light blue streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Lazurite?
Lazurite has a Mohs hardness of 5.25. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
What is the difference between Lazurite and Lapis Lazuli?
Lazurite (Mohs 5.25, vitreous luster) and Lapis Lazuli (Mohs 5.5, vitreous luster) look alike, but hardness, streak and heft usually separate them. See the full Lazurite vs Lapis Lazuli comparison for a side-by-side table.
Is Lazurite worth anything?
Entry-level Lazurite specimens sell for around $10, typical collector pieces about $80, and premium examples $600 or more depending on size, quality and locality.
What color is Lazurite?
Lazurite is most often blue, deep blue, azure blue, and violet blue. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
