Copper carbonate in concentric green bands. Soft, dense, fizzes in acid, and imitated in resin constantly.
The Democratic Republic of the Congo, Zambia, Morocco, Arizona6 field tests
Malachite is a copper carbonate, and it is one of the few minerals whose identity is genuinely written on its surface. The banding — light and dark green in concentric rings, botryoidal bubbles, and eye or bullseye patterns — records the mineral growing outward in layers from many centres at once, in a cavity, over a long time.
It is also soft, at 3.5 to 4 on the Mohs scale, which places it below a steel knife and just above a copper coin. That softness has a practical consequence worth knowing before you buy: malachite scratches in normal wear, dust from working it is genuinely toxic to inhale because it is a copper compound, and it should never be cleaned in an ultrasonic bath or with acid.
Because the banding is the whole appeal and the material is expensive relative to its abundance, the market carries a large volume of imitation. Almost all of it is polymer — resin or plastic with green pigment swirled through it — and almost all of it fails on weight, hardness and one drop of vinegar.
Malachite is a carbonate, which is the single most useful thing about identifying it. Carbonates effervesce in acid, and no polymer, no dyed stone and no glass does. A drop of household vinegar on an inconspicuous spot, watched under a hand lens, will produce slow fine bubbles on genuine malachite.
Do it on the back of a piece and wipe it dry immediately. Acid etches malachite, so this test leaves a small dull patch — which is why it goes somewhere invisible and is done once.
| Property | Malachite | What it separates it from |
|---|---|---|
| Mohs hardness | 3.5 – 4 | A steel knife cuts it; polymer imitations are softer still |
| Streak | Pale green | Dyed stone streaks white; resin gives no streak |
| Specific gravity | 3.6 – 4.0 | Resin about 1.2 — a vast difference in the hand |
| Reaction to dilute acid | Effervesces — fine slow bubbles | Resin, glass, dyed serpentine: no reaction |
| Banding | Concentric, botryoidal, with visible growth centres | Resin: swirled, wandering, no radial structure |
| Cleavage | Perfect in one direction, rarely seen | — |
| Feel | Cool, dense, distinctly stone-like | Resin warms to the hand in a second |
| Dust | Toxic — copper compound. Do not dry-grind it | A safety note rather than a test |
Weight and the acid test together are conclusive against every common imitation. The banding structure catches the good ones.
Ordered by how much each one proves. The decisive tests are worth your first two minutes; the supporting ones only matter once those agree.
This is the fastest test and it catches most of the market. Malachite's specific gravity is 3.6–4.0, which is heavy — noticeably heavier than quartz and about three times the density of the polymer resins used to imitate it. A resin fake of any size feels immediately, unmistakably too light. Pick the piece up before you look at it.
Malachite is a carbonate and effervesces in weak acid. Use household vinegar on the back or base, and watch under a hand lens for fine slow bubbles rather than expecting visible foam. Resin, glass, dyed serpentine and dyed howlite do nothing. Wipe it dry at once, because acid etches the surface and leaves a dull mark.
Genuine malachite grew outward from many nucleation points, so its bands are concentric around visible centres, forming eyes, bullseyes and grape-like botryoidal bulges. Follow a band with a fingertip: it should close on itself around a centre. Resin imitations have swirled, marbled, wandering bands that never resolve into concentric rings, because they were stirred rather than grown.
At 3.5–4 malachite takes a blade and yields a pale green powder — which is also a streak test, since the powder colour is diagnostic. Resin gives a curl or shaving rather than powder, and often a slightly waxy one. Dyed white stone gives white powder under a green skin.
Resin imitations are cast, so check the piece's edge and base for a faint seam, a sprue mark, or a flat unfinished face where it sat in the mould. Under a loupe, cast resin frequently contains round trapped bubbles. Neither occurs in a mineral that was cut from rock.
There is a middle category: genuine malachite ground to powder and bound in resin, pressed and cut. It contains real malachite, so it may fizz faintly and weigh more than pure resin, but it is a composite. The tell is banding that is granular rather than layered under a loupe, and a weight that sits between resin and solid stone.
Malachite's imitation market is unusually blatant because the pattern is easy to approximate and the material is instantly recognisable. Pigmented polyester resin does most of the work, cast into eggs, spheres, pyramids and slabs, and it is often not even described as malachite so much as photographed to look like it.
The reason it works at all is that photographs flatten out the two things that give it away: the weight and the structure of the bands. In the hand, a resin egg is a toy. On a screen, it is convincing.
Each of these is checked differently. The ones with their own page have enough that is specific to them to be worth reading separately.
Malachite powder bound in resin. Real material, manufactured object.
Read within the checks aboveSpecimen figures rather than gem figures, for material in honest condition. Most finds are worth very little, and saying so plainly is more useful than encouraging you.
| Form | What it typically fetches | Note |
|---|---|---|
| Resin imitation | Nothing | A few dollars, and worth that as an ornament |
| Tumbled or small polished piece | $3 – 15 | Sold by weight |
| Polished slab or freeform, hand-sized | $25 – 150 | Banding quality and polish |
| Botryoidal specimen, Congo | $50 – 500 | Undamaged bubble surfaces |
| Fine cabinet specimen with velvet crystals | $300 – 2,000+ | Crystal form is far rarer than banded massive |
Banded massive malachite is decorative stone and priced as such. What commands real money is crystalline malachite — fibrous velvet or sharp crystals — which is a genuinely scarce habit.
Lovenhall StoneThe tests tell you what it is. The instrument reads a photograph and offers a name to start from — then hands you back to the tile and the coin, which are what settle it.