Andesine is a member of the plagioclase feldspar solid solution series, falling between oligoclase and labradorite in chemical composition. It is commonly found as a rock-forming mineral in intermediate volcanic and plutonic rocks, appearing as white to grey grains in the field.
Is this andesine?
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 andesine with a known reference. Andesine sits at Mohs 6-6.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Andesine leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Andesine typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, gray, greenish, yellowish, reddish.
- 5Look at form & habitCrystal system: triclinic. Typical habit: tabular crystals, massive, granular.
Often confused with
Andesine vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside andesine
Minerals reported to co-occur with andesine. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Na,Ca)(Si,Al)₄O₈
- Mohs hardness
- 6-6.5
- Density
- 2.66-2.68 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Triclinic
- Crystal habit
- Tabular Crystals, Massive, Granular
- Cleavage
- Perfect On {001}, Good On {010}
- Rarity
- Common
- Uses
- Collector, Geological Study
- Host rock
- Igneous Rocks Such as Andesite, Diorite, And Dacite
- Typical price
- $5-30 for typical specimens
Where rockhounds find andesine
2 mapped spotsClassic worldwide localities
- Andes Mountains, South America
- Oregon, USA
- Norway
- Scotland
- Germany
Field-hunting tip
Look in igneous rocks such as andesite, diorite, and dacite country, the host setting where andesine typically forms. If you start seeing quartz, biotite, hornblende in float, you are in the right ground. Field specimens usually show a tabular crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Idaho, Utah. Start trip planning there.
Common questions
How do you identify andesine?+
Where is andesine found?+
Can I find andesine in the United States?+
How much is andesine worth?+
What rocks look like andesine?+
What minerals are found with andesine?+
What kind of rock does andesine form in?+
What is andesine used for?+
Find andesine on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
