Lazurite is the essential blue component of the ornamental stone known as Lapis Lazuli. It typically appears as deep blue, granular masses within marble and is frequently accompanied by glittering flecks of pyrite and white calcite inclusions.
Is this lazurite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch lazurite with a known reference. Lazurite sits at Mohs 5-5.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: bright blue.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: blue, azure, violet-blue, azure blue, greenish blue.
- 5Look at form & habitCrystal system: cubic. Typical habit: massive.
Often confused with
Lazurite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Lazurite leaves bright blue, Sodalite leaves white.
How to tell apart: Streak differs, so Lazurite leaves bright blue, Haüyne leaves slightly bluish to colorless.
How to tell apart: Lazurite is noticeably harder (Mohs 5-5.5 vs. 3.5-4); streak differs, so Lazurite leaves bright blue, Azurite leaves pale blue.
Often found alongside lazurite
Minerals reported to co-occur with lazurite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₇Ca(Al₆Si₆O₂₄)(SO₄)(S₃)·H₂O
- Mohs hardness
- 5-5.5
- Density
- 2.38-2.45 g/cm³
- Streak
- Bright blue
- Luster
- Vitreous
- Transparency
- Translucent to opaque
- Crystal system
- Cubic
- Crystal habit
- Massive
- Cleavage
- {110}, imperfect
- Rarity
- Uncommon
- Uses
- Gemstone, Lapidary, Decorative, Collector
- Host rock
- A contact metamorphic mineral in limestones
Where rockhounds find lazurite
Classic worldwide localities
- Ontario Peak and Cascade Canyon, San Bernardino Co., California, and on North Italian Mountain, Gunnison Co., Colorado, USA
- Sar-e-Sang, Badakhshan Province, Afghanistan
- Basins of the Slyudyanka and Bystraya Rivers, Sayan Mountains, near Lake Baikal, Siberia, Russia
- Lyadzhuar-Darinsk, near Ishkashima, Pamir Mountains, Tajikistan
- Monte Somma, Campania, and in the Alban Hills, Lazio, Italy
- Thabapin, near Mogok, Myanmar (Burma)
Field-hunting tip
Where it forms: A contact metamorphic mineral in limestones. If you start seeing calcite, pyrite, diopside in float, you are in the right ground. Typical habit: massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify lazurite?+
Where is lazurite found?+
What rocks look like lazurite?+
What minerals are found with lazurite?+
What kind of rock does lazurite form in?+
What is lazurite used for?+
Find lazurite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
