Olivine is a magnesium-iron silicate typically occurring as olive-green grains in basaltic lavas or plutonic peridotites. While common as a rock-forming mineral, gem-quality specimens are known as peridot and are prized for their vibrant, lime-green color. Collectors often seek out large, glassy grains found in volcanic sands or intact crystals from xenoliths.

Hardness
6.5-7
Mohs
Luster
Vitreous
Streak
White
Transparency
Transparent

Is this olivine?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

  • 1
    Test the hardness
    Try to scratch olivine with a known reference. Olivine sits at Mohs 6.5-7, softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Streak: white.
  • 3
    Read the luster
    Hold the specimen under a strong light. Luster: vitreous.
  • 4
    Match the color range
    Compare against the expected color range: olive green, yellow-green, brownish green, yellow, yellowish green, greenish black, reddish brown.
  • 5
    Look at form & habit
    Crystal system: orthorhombic. Typical habit: massive.

Often confused with

Olivine vs. its common look-alikes, and how to tell them apart in the field.

Often found alongside olivine

Minerals reported to co-occur with olivine. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula
(Mg,Fe)₂SiO₄
Mohs hardness
6.5-7
Density
3.27-3.37 g/cm³
Streak
White
Luster
Vitreous
Transparency
Transparent
Crystal system
Orthorhombic
Crystal habit
Massive
Cleavage
Good on {001}; distinct on {010}
Rarity
Common
Uses
Gemstone, Collector, Industrial
Host rock
Basic and ultra basic igneous rocks

Where rockhounds find olivine

8 mapped spots

Classic worldwide localities

  • Zabargad Island, Egypt
  • San Carlos, Arizona, USA
  • Kohistan, Pakistan
  • Norway
  • Hawaii, USA

Field-hunting tip

Where it forms: Basic and ultra basic igneous rocks. If you start seeing pyroxene, plagioclase, chromite in float, you are in the right ground. Typical habit: massive. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in North Carolina, Alabama, California. Start trip planning there.

More olivine photos

  • Olivine
  • Olivine as a mantle xenolith in basalt

Common questions

How do you identify olivine?+
Mohs hardness is 6.5-7. Luster: vitreous. The streak is white. Common colors include olive green, yellow-green, brownish green, yellow.
Where is olivine found?+
Notable localities include Zabargad Island, Egypt; San Carlos, Arizona, USA; Kohistan, Pakistan; Norway; Hawaii, USA.
Can I find olivine in the United States?+
RockHoundR maps 8 olivine rockhounding spots across 7 U.S. states. The top states are North Carolina, Alabama, California.
What rocks look like olivine?+
Olivine is most often confused with Diopside, Epidote, Chrysoberyl. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with olivine?+
Olivine commonly co-occurs with Pyroxene, Plagioclase, Chromite, Serpentine. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does olivine form in?+
Where it forms: Basic and ultra basic igneous rocks. Working float back to the host body is the standard way to chase a fresh occurrence.
What is olivine used for?+
Olivine is used in gemstone, collector, industrial.

Find olivine on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.

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