Named after the mine, loved for its blue

Shattuckite got its name from the Shattuck mine in Bisbee (Arizona), where it was first described. As a secondary copper mineral, it forms by oxidation of primary ores (e.g., chalcopyrite or bornite) near the surface. The result: pretty, blue coatings and masses, polished to resemble fabric.

What it is not

Shattuckite is not the same as chrysocolla (also a bluish-green copper silicate, but usually earthier, yellowish in texture) or plancheite (a harder, fibrous copper silicate). They often grow together — which adds beauty but sometimes causes identification puzzles.

Oxidation zone specialist

Chalcotrichite grows when copper sulfides weather under silicon-rich solutions. It lines fractures, voids, and breccia cavities with fibrous crusts or spherical aggregates.

Help from silicon

Silica-saturated fluids can permeate blue masses and turn them into "chalcotrichite in quartz". Quartz "locks in" the color and strengthens the stone — great news for cutters and jewelers.

Pseudomorph stories

In some deposits, chalcotrichite can replace earlier copper minerals, preserving their shapes (pseudomorphs) — a mineralogical "cosplay" favored by collectors.

Palette

• Sky to indigo blue — classic, rich chalcotrichite.
• Bluish green — when chemistry changes or partners join (chrysocolla).
• Malachite green — frequent companions in tapestry bands.
• Quartz white/gray — silicified areas adding strength and shine.

In masses expect soft, fibrous texture; quartz surface is glassy, and the blue "clouds" beneath it.

Pattern terms

• Velvet fields — uniform blue, felt texture, polishes to satin.
• Tapestry — intertwined patch of chalcotrichite–chrysocolla–malachite.
• Cloud lace in quartz — floating blue threads and nets under clear silica.
• Rosettes — radial fans, sometimes with a silky sheen when tilted.

Photo tip: Side light (~25–30°) highlights the velvet fuzz; soft additional lighting prevents the blue in the camera from turning completely black.

Fibrous “fluff”

At 10×, look for microfibers and felt textures. Radial rosettes look like tiny fans; aligned fibers tilted give a subtle silky sheen.

Signs of the quartz host

In “Shattuckite in quartz” the blue lies under a glassy surface, healed fractures and fine reflective planes are visible — proof that silicon did the hard work.

We distinguish blues

Chrysocolla is more often earthy and patchy; plancheite forms larger radial brushes and is usually harder. When mature, the final verdict is given by labas (Raman spectroscopy); visually, the velvet fineness indicates shattuckite.

Chrysocolla

Similar palette but generally softer (2–4) and more porous/earthy. Both look bright in quartz — then shade and texture become clues.

Plancheite

Also blue, fibrous copper silicate, but tends to form broom-like radial fans and is noticeably harder. Often found with chrysocolla in “Copperbelt” associations.

Azurite / Ajoite / Hemimorphite

Azurite — deeper royal blue with crystalline sparkle; ajoite in quartz tends toward greenish blue with “phantom” veins; hemimorphite can be sky blue but has different weight and chemistry.

Turkish

Harder, waxy luster, and different structure; turquoise rarely forms the velvety fibrous masses typical of chrysocolla.

Glass and dyes

Dyed materials often have too uniform color and clumping in cracks. Chrysocolla blue is within the fibers, not just on the surface.

Quick checklist

• Velvety blue with fine fibers at 10×?
• Heavier than chalk (SG about 4)?
• Glassy surface, because blue in quartz? → very suitable for wearing.

Classic sources

Bisbee, Arizona (typical), northern Namibia's Kaokoveld (famous “chrysocolla in quartz”), Tsumeb (Namibia), and Katanga Copperbelt (DR Congo) — well known. Smaller finds occur wherever copper meets silica and weathering.

How it is sold

Like cabochons, beads, tumbled stones, and decorative slabs. Stabilized materials exist for even gloss; top quality — naturally silicified blue in quartz.

Daily care

• Clean with lukewarm water + mild soap; soft cloth; dry quickly.
• Avoid acids, aggressive cleaners, and prolonged soaking (porous!).
• Do not use ultrasound/steam; keep away from harder gems to protect the surface.

Jewelry guidelines

• Best for pendants and earrings. For rings/bracelets, choose bezel settings and wear carefully — unless it's blue locked in quartz.
• White metals highlight blue; yellows create a Mediterranean mood.
• In composites (with chrysocolla/malachite), design considering hardness contrasts.

Polishing

• Work cool and gently. Pre-polish 600→1200→3k; avoid heavy pressure (fibers can "shift").
• To finish — aluminum oxide or cerium on a soft pad; microcrystalline wax can improve stain resistance.
• Silicified material achieves a clear, glassy shine — treat it like quartz and let the blue glow from within.

Fuzz under the loupe

At 10×, look for velvet-fine fibers. Rotate the stone in side lighting — some rosettes will show a gentle, silky flash.

Light up the quartz from behind

Illuminate shattuckite in quartz from behind. The blue floats like clouds and nets in the transparent host — small air pockets in the stone.