Shattuckite

Shattuckite is a rare copper silicate hydroxide mineral known for its rich blue to blue-green color. It was first described in 1915 from the Shattuck Mine in Bisbee, Arizona, which gives the mineral its name.

Shattuckite is usually found in massive, fibrous, or botryoidal forms rather than distinct crystals, and it frequently occurs intergrown with other copper minerals such as malachite, chrysocolla, azurite, quartz, and the closely related mineral plancheite. It is a secondary copper mineral.

Because attractive, solid blue material is uncommon, shattuckite is valued by collectors and is occasionally cut into cabochons, sometimes within a quartz or chrysocolla matrix ("shattuckite in quartz").

Shattuckite forms as a secondary mineral in the oxidized zones of copper ore deposits, where copper-bearing primary minerals weather and react with silica-rich groundwater. It commonly develops by alteration of earlier copper minerals such as malachite and azurite, sometimes pseudomorphously replacing them while preserving their shapes.

It occurs in fibrous mats, botryoidal crusts, and massive aggregates lining cavities and fractures in the host rock. Notable localities include Bisbee, Arizona (the type locality), and significant deposits in Namibia (the Kandesei and Kaokoveld areas) and the Democratic Republic of Congo, which produce much of the fine collector and lapidary material.

Look for a deep blue to blue-green mineral occurring in fibrous, massive, or botryoidal habits, often intergrown with green malachite and lighter blue chrysocolla, with a hardness of only 3.5-4 and a pale blue streak.

It has a silky to dull luster and is associated with other copper minerals. Its low hardness separates it from harder blue stones like lapis lazuli (5-5.5) and sodalite.

The most difficult look-alike is plancheite, a closely related copper silicate of very similar color and habit; the two are often hard to tell apart without analysis. Chrysocolla is generally lighter blue-green and softer/more variable, while azurite is a brighter, deeper blue with a different crystal habit.

Shattuckite is primarily a collector's mineral, prized for its intense blue color and association with other copper minerals. Solid or attractively patterned material is cut into cabochons and beads for jewelry, sometimes stabilized or left within a quartz matrix because the mineral itself is fairly soft.

It has no major industrial use, though it is a minor copper-bearing mineral of mineralogical interest. Value depends on color saturation, solidity, and locality, with fine Namibian and Congolese material sought after.

In the metaphysical market it is marketed as a communication and intuition stone for the throat and third-eye chakras, though these claims are not scientific.