Identification guide · Semi-Precious Stones
How to Identify Lapis Lazuli
Lapis Lazuli is usually deep blue, blue, and blue with gold flecks with a vitreous luster and is opaque. It has a Mohs hardness of 5.5. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. Its streak is light blue. It is most often confused with Lazurite, Calcite, and Pyrite; the tests below separate them.
Lapis Lazuli identification checklist
| Color | Deep Blue, Blue, Blue with gold flecks | 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 | Opaque | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 5.5 | It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. |
| Streak | Light blue | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | Poor | |
| Fracture | Uneven | |
| Specific gravity | 2.8 | Ordinary rock-like heft (specific gravity about 2.8), similar to quartz. |
| Crystal system | Cubic |
Lapis Lazuli look-alikes and how to tell them apart
Both sit near Mohs 5.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Lapis Lazuli vs Lazurite →
Lapis Lazuli is harder (Mohs 5.5) than Calcite (Mohs 3), so Lapis Lazuli will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Lapis Lazuli vs Calcite →
Pyrite is harder (Mohs 6.5) than Lapis Lazuli (Mohs 5.5), so Pyrite will scratch Lapis Lazuli and not the other way round. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. Lapis Lazuli vs Pyrite →
Both sit near Mohs 5.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Is my Lapis Lazuli real?
- Hardness: real Lapis Lazuli sits at Mohs 5.5. Glass imitations are about 5.5, so use a steel file and a known reference mineral rather than glass alone.
- Bubbles: round gas bubbles under a 10x loupe mean glass or resin, never a natural stone.
- Color: dyed material concentrates color in cracks and pores; look for pigment collecting at the edges of fractures.
- Temperature: natural crystals feel cool and take longer to warm in your hand than plastic or resin.
Field tips
- Check whether the specimen's color and texture match typical Lapis Lazuli examples.
- Use hardness, streak, luster, grain size, and locality together; no single trait is enough for every specimen.
Lapis Lazuli identification FAQ
How can you tell if a rock is Lapis Lazuli?
Check the color (deep blue, blue, and blue with gold flecks), the vitreous luster, a Mohs hardness of 5.5 and a light blue streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Lapis Lazuli?
Lapis Lazuli has a Mohs hardness of 5.5. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will.
What is the difference between Lapis Lazuli and Lazurite?
Lapis Lazuli (Mohs 5.5, vitreous luster) and Lazurite (Mohs 5.25, vitreous luster) look alike, but hardness, streak and heft usually separate them. See the full Lapis Lazuli vs Lazurite comparison for a side-by-side table.
How do I know if my Lapis Lazuli is real?
Real Lapis Lazuli matches the hardness listed above, shows no round gas bubbles under magnification, and does not concentrate dye in cracks. Glass and resin fakes fail at least one of those checks.
Is Lapis Lazuli worth anything?
Entry-level Lapis Lazuli specimens sell for around $10, typical collector pieces about $50, and premium examples $500 or more depending on size, quality and locality.
What color is Lapis Lazuli?
Lapis Lazuli is most often deep blue, blue, and blue with gold flecks. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
