Smaragdite is a chromium-rich, emerald-green variety of actinolite or hornblende commonly associated with corundum. It is most often found as a fine-grained, massive constituent within eclogite or metamorphic rocks, favored by lapidary artists for carving.
Is this smaragdite?
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 smaragdite with a known reference. Smaragdite sits at Mohs 5-6, 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: emerald green, grass green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: fibrous.
Often confused with
Smaragdite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside smaragdite
Minerals reported to co-occur with smaragdite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂(Mg,Fe²⁺)₅Si₈O₂₂(OH)₂
- Mohs hardness
- 5-6
- Density
- 3.2-3.4 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Fibrous
- Cleavage
- Perfect in two directions
- Rarity
- Uncommon
- Uses
- Collector, Lapidary
- Host rock
- metamorphic
Where rockhounds find smaragdite
2 mapped spotsClassic worldwide localities
- Austria
- Italy
- North Carolina, USA
- Norway
Field-hunting tip
Where it forms: metamorphic. If you start seeing corundum, zoisite, plagioclase in float, you are in the right ground. Typical habit: fibrous. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in North Carolina. Start trip planning there.
Common questions
How do you identify smaragdite?+
Where is smaragdite found?+
Can I find smaragdite in the United States?+
What rocks look like smaragdite?+
What minerals are found with smaragdite?+
What kind of rock does smaragdite form in?+
What is smaragdite used for?+
Find smaragdite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
