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.
Is this olivine?
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 olivine with a known reference. Olivine sits at Mohs 6.5-7, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: olive green, yellow-green, brownish green, yellow, yellowish green, greenish black, reddish brown.
- 5Look at form & habitCrystal 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 spotsClassic 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.









