carbonates
Malachite
Cu2(CO3)(OH)2
- Also known as
- azurmalachitecopper carbonate
- Crystal system
- monoclinic
- Hardness
- 3.5–4 on the Mohs scale
- Lustre
- silky
- Colour
- Banded bright green to near black
- Where it forms
- In the oxidised upper zone of copper ore bodies, where descending groundwater carrying dissolved carbon dioxide reacts with copper sulfides beneath.
- Chiefly from
- Katanga, Democratic Republic of the CongoUral Mountains, RussiaArizona, United States
Why it is that colour
Copper. The banding records successive depositions from changing groundwater, in the same way as an agate but with a copper carbonate instead of silica.
Safety
Solid polished malachite is safe to hold. Everything else about it is not. It is a copper carbonate, it dissolves in weak acid including vinegar and stomach acid, and it is soft enough to abrade into dust with ordinary handling. Copper is toxic in quantity. Do not make an elixir with it, do not use it in a mortar, and do not cut or sand it without extraction — malachite dust is a recognised lapidary hazard.
Where it comes from
Congolese material from the Katanga copper belt dominates the specimen market. Katangan mining includes very large artisanal and small-scale operations with documented child labour, chiefly reported in connection with cobalt, which comes out of the same ore bodies. A malachite ornament and a cobalt battery can share a mine.
Historical use
One of the oldest pigments known — the green of Egyptian tomb painting and of much medieval European work is ground malachite. It was also a copper ore, and probably one of the first, since it is conspicuous and smelts easily. The malachite room at the Hermitage and the columns of St Isaac’s Cathedral are Russian Ural material, veneered rather than solid.
Recorded as history and attributed where possible. That a stone was used for something establishes that people used it, not that it worked.
What is attributed to it, and since when
Ground malachite was the green eye paint of ancient Egypt, and Egyptian sources treat it as protective. Pliny records it as a stone for children. That protective reading carries forward through Russian and European folk use. What is modern is the specific package of transformation and heart-opening, which is New Age.
Described, not endorsed. Dating a claim is not the same as assessing it — but an association that first appears in a book published in 1985 is not an ancient inheritance, whatever the label says. A sincere account of feeling better is compatible with the stone doing nothing — see the placebo effect.
Sold as this, but not
Worth knowing
Malachite is the strongest argument in this collection for keeping a toxicity field. It is beautiful, it is cheap, it is everywhere in wellbeing shops, and it is a soft copper salt that dissolves in acid. Instructions for making malachite elixirs are readily findable online, and the better crystal books have been warning against exactly this for thirty years without much effect.
The pigment history is a nice illustration of the same chemistry from the other side. Malachite green was prized by painters and hated by conservators, because it is unstable — it darkens, and in some conditions it converts to other copper compounds. The property that makes a pigment fugitive and the property that makes a stone unsafe in water are the same property.
Identity checked against IMA-CNMNC master list, June 2025.