Achondrites are stony meteorites that lack chondrules and have been differentiated by igneous processes on a parent body. They typically resemble terrestrial igneous rocks like basalt, making identification difficult without chemical analysis or identification of a fusion crust. They are highly sought after by meteorite collectors and scientific institutions.
Is this achondrite?
6-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 achondrite with a known reference. Achondrite sits at Mohs 5-7, softer than the next harder reference, harder than the previous one.
- 2Read the textureLook at a fresh break with a hand lens. Texture: Igneous textures; no chondrules.
- 3Pick out the mineralsComposition: Material similar to terrestrial basalts or plutonic rocks. Identify the two or three most abundant grains.
- 4Check the streakDrag the specimen across an unglazed porcelain plate. Streak: none, or a weak grayish streak if pressed hard.
- 5Read the lusterHold the specimen under a strong light. Luster: dull.
- 6Match the color rangeCompare against the expected color range: gray, brown, black, greenish.
Often confused with
Achondrite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside achondrite
Minerals reported to co-occur with achondrite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Mohs hardness
- 5-7
- Density
- 2.9-3.5 g/cm³
- Streak
- None, or a weak grayish streak if pressed hard
- Luster
- Dull
- Transparency
- Opaque
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- extraterrestrial
- Texture
- Igneous textures; no chondrules
- Composition
- Material similar to terrestrial basalts or plutonic rocks
Where rockhounds find achondrite
Classic worldwide localities
- Antarctica
- Sahara Desert
- Northwest Africa
Field-hunting tip
Where it forms: extraterrestrial. If you start seeing olivine, pyroxene, plagioclase in float, you are in the right ground.
Common questions
How do you identify achondrite?+
Where is achondrite found?+
What rocks look like achondrite?+
What minerals are found with achondrite?+
What kind of rock does achondrite form in?+
What is achondrite used for?+
Find achondrite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
