How to Identify Azurite-Malachite

Azurite and malachite are both copper carbonates and azurite converts to malachite over time as it takes up water, which is why the two so often occur in the same specimen with the blue giving way to green at the edges and along fractures. A piece showing both is a snapshot of that conversion in progress.

This is useful for identification because it is hard to fake convincingly. The boundary between blue and green in genuine material follows the alteration front — it invades from the outside and along cracks, it is irregular, and the green is often botryoidal where it has grown. A pigmented resin shows blue and green swirled together with no directional logic.

Azurite is slightly softer than malachite at 3.5–4 and also fizzes in acid, so both halves of a genuine specimen respond to the carbonate test. A piece where only one colour reacts is a composite.