Ajoite is a stunning, rare copper silicate mineral highly sought after by collectors for its vibrant blue-green color. It most frequently appears as delicate, fibrous sprays or tufts included within clear quartz crystals, especially those from the Messina district. It is a secondary mineral formed by the oxidation of copper deposits and is typically found in small amounts.
Is this ajoite?
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 ajoite with a known reference. Ajoite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Ajoite leaves a pale blue streak.
- 3Read the lusterHold the specimen under a strong light. Ajoite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: blue, greenish-blue.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: sprays, radiating clusters, fibrous aggregates.
Often confused with
Ajoite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside ajoite
Minerals reported to co-occur with ajoite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (K,Na)Cu₇AlSi₉O₂₄(OH)₆·3H₂O
- Mohs hardness
- 3.5
- Density
- 2.96 g/cm³
- Colors
- Streak
- Pale Blue
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Sprays, Radiating Clusters, Fibrous Aggregates
- Cleavage
- Perfect On {010}
- Rarity
- Rare
- Uses
- Collector, Metaphysical Specimen
- Host rock
- Hydrothermal Veins in Oxidized Copper Deposits
- Typical price
- $50-500+ depending on size and association with quartz
Where rockhounds find ajoite
Classic worldwide localities
- Ajo, Arizona, USA
- Messina, South Africa
Field-hunting tip
Look in hydrothermal veins in oxidized copper deposits country — that is the host setting where ajoite typically forms. If you start seeing quartz, papagoite, shattuckite in float, you are in the right ground. Field specimens usually show a sprays, radiating clusters, fibrous aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ajoite?+
Where is ajoite found?+
How much is ajoite worth?+
What rocks look like ajoite?+
What minerals are found with ajoite?+
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Find ajoite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
