Maricopaite is a rare lead-calcium silicate often found as delicate, white, radiating sprays of needle-like crystals. It is primarily known from the Hilltop Mine in Arizona, where it occurs as a secondary mineral in oxidized ore zones.
Is this maricopaite?
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 maricopaite with a known reference. Maricopaite sits at Mohs 1-2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Maricopaite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Maricopaite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: acicular crystals, radiating sprays.
Often confused with
Maricopaite vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Mimetite is the harder of the two (Mohs 3.5-4 vs. 1-2); luster reads vitreous on Maricopaite and adamantine on Mimetite.

How to tell apart: Cerussite is the harder of the two (Mohs 3-3.5 vs. 1-2); luster reads vitreous on Maricopaite and adamantine on Cerussite.
Often found alongside maricopaite
Minerals reported to co-occur with maricopaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₈(Si₈Al₂)O₂₀(OH)₄·8H₂O
- Mohs hardness
- 1-2
- Density
- 2.33 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Acicular Crystals, Radiating Sprays
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Lead-zinc Ore Deposits
- Typical price
- $50-500 depending on specimen quality and matrix
Where rockhounds find maricopaite
Classic worldwide localities
- Hilltop Mine, Cochise County, Arizona, USA
Field-hunting tip
Look in oxidized lead-zinc ore deposits country — that is the host setting where maricopaite typically forms. If you start seeing mimetite, wulfenite, cerussite in float, you are in the right ground. Field specimens usually show a acicular crystals, radiating sprays habit, so train your eye for that shape before scanning the outcrop.



