Azurite

Azurite is traditionally associated with intuition, revelation, spiritual awakening, the opening of the third eye, seeing the truth, inner insight, focus and creativity. From its long history as a treasured blue mineral and the deep azure that symbolizes the third eye, it has been cherished as a “stone that opens inner sight”.

Azurite is not a designated birthstone in Japan, nor a designated anniversary stone. In Japan it is chosen as non-birthstone mineral jewelry by those drawn to its blue tied directly to art history and to its sisterhood with malachite.

Azurite Cu₃(CO₃)₂(OH)₂ and malachite Cu₂(CO₃)(OH)₂ are kindred secondary copper carbonates that form in the oxidized zone of copper deposits. They differ only in the ratio of copper to carbonate, and the CO₂ pressure of formation splits them into blue (azurite) and green (malachite) — azurite where CO₂ is abundant, malachite where it has escaped. The two frequently intergrow, including the banded blue-and-green occurrence called azurmalachite. Azurite is also known to be pseudomorphously replaced by malachite over long periods while keeping its crystal shape — famous as the cause of the blue-to-green change in museum specimens and old paintings.

In Michelangelo’s *Entombment* and many other 15th–17th-century European paintings, blue robes are now greenish. This is not paint decay but the result of the era’s key blue pigment, azurite, being pseudomorphously replaced by malachite over decades to centuries of exposure to air and humidity. The reaction, 2Cu₃(CO₃)₂(OH)₂ + H₂O → 3Cu₂(CO₃)(OH)₂ + CO₂, takes in atmospheric moisture and releases CO₂, turning blue (azurite) to green (malachite). It is a fascinating phenomenon at the border of art history and mineralogy, and a major topic in modern art conservation.

As a carbonate, azurite Cu₃(CO₃)₂(OH)₂ is sensitive to acid, ammonia, prolonged water, heat and direct sun. Avoid sweat (acidic), vinegar, lemon juice, ammonia-based cleaners, steam cleaners and ultrasonic cleaners. Because it also alters to malachite (greens) over long periods, separate storage somewhere with little humidity and a dry wipe after wear keep it beautiful longer. At Mohs 3.5–4 it is brittle and can break under impact, so take it off where it might be knocked and store it in its own case so it does not touch other stones.

As natural-stone jewelry, azurite is used for raw-stone earrings, necklaces and brooches. As a relatively brittle mineral at Mohs 3.5–4 it can break under impact, so take it off where it might be knocked and store it in its own case so it does not touch other stones. TROZO makes azurite jewelry that keeps the raw stone unpolished so its crystal faces and deep azure lead the design — both pieces you can choose by color and crystal form from stock, and pieces where the meeting with the stone is left to chance.

Chessy-les-Mines near Lyon, France was the 19th-century type locality and the source of the name Chessylite. Morocco (Touissit, Mibladen) yields clear deep-blue single crystals of the world’s finest, and Namibia (the Tsumeb mine) large velvety crystals. It is also found in Arizona, USA (Bisbee, Morenci — with malachite), Mexico, Australia (Broken Hill), China and Russia.

The name Azurite traces from Old French azur (sky-blue) to Arabic lāzaward to Persian lāžaward — the very same root as lapis lazuli; the English color word azure is of the same root. They are siblings even in language, sharing humankind’s word for “blue”. As minerals, though, they are quite different: lapis lazuli is a rock (an aggregate of several minerals) with lazurite as its main component, while azurite is a single copper carbonate mineral.