Richelsdorfite is a rare copper-calcium-antimony arsenate mineral that forms as a secondary product in the oxidation zones of copper deposits. It is best identified by its vibrant blue to bluish-green bladed or radial crystal clusters typically found in small vugs.
Is this richelsdorfite?
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 richelsdorfite with a known reference. Richelsdorfite sits at Mohs ~2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: greenish blue.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: sky blue, turquoise.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: bladed crystals, radial aggregates, crusts.
Often confused with
Richelsdorfite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Richelsdorfite leaves greenish blue, Liroconite leaves pale blue to pale green.
How to tell apart: Mixite is the harder of the two (Mohs 3-4 vs. ~2); streak differs, so Richelsdorfite leaves greenish blue, Mixite leaves pale bluish green.
Often found alongside richelsdorfite
Minerals reported to co-occur with richelsdorfite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂Cu₅Sb(AsO₄)₄(OH)₆Cl(H₂O)₅·H₂O
- Mohs hardness
- ~2
- Density
- 3.20 g/cm³
- Streak
- Greenish blue
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Bladed crystals, radial aggregates, crusts
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In cavities in sandstone in the Kupferschiefer (Richelsdorf Mountains, Germany)
Where rockhounds find richelsdorfite
Classic worldwide localities
- Burrus mine, Pyramid district, Washoe Co., Nevada, USA
- Iba, near Richelsdorf, Richelsdorf Mountains, and Reichenbach, near Bensheim, Hesse, Germany
- Sauberg mine, Ehrenfriedersdorf, Saxony, Germany
- Samson mine, St. Andreasberg, and on the dumps of the Glücksrad mine, Oberschulenberg, Harz Mountains, Germany
- Alte Buntekuh mine, near Niederschelden, and at Ramsbeck, North Rhine-Westphalia, Germany
- Clara mine, near Oberwolfach, Black Forest, Germany
Field-hunting tip
Where it forms: In cavities in sandstone in the Kupferschiefer (Richelsdorf Mountains, Germany). If you start seeing duftite, tyrolite, azurite in float, you are in the right ground. Typical habit: bladed crystals, radial aggregates, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify richelsdorfite?+
Where is richelsdorfite found?+
Is richelsdorfite safe to handle?+
What rocks look like richelsdorfite?+
What minerals are found with richelsdorfite?+
What kind of rock does richelsdorfite form in?+
What is richelsdorfite used for?+
Find richelsdorfite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
