This calcite cluster from the Daye copper mining district in Hubei Province, China displays a striking natural rainbow sheen created by microscopic coatings of chalcopyrite and pyrite across the crystal surfaces. Unlike artificial aura treatments, the iridescence here is entirely natural, formed through subtle oxidation processes that developed directly on the calcite after crystal growth.

As the specimen shifts under light, each calcite face reflects layered metallic tones of gold, violet, green, and soft pink. The crisp rhombohedral geometry of the calcite contrasts beautifully with the ultra-fine metallic crust, producing exceptional surface texture and visual depth. Under magnification, the glittering mosaic of micro-sulfide crystals becomes clearly visible, revealing the true source of the rainbow effect.

Weight: 494 g (1.09 lb)
Size: 113 × 89 × 60 mm (4.45 × 3.50 × 2.36 in)

A meaningful addition for collectors who value Daye calcite for its natural metallic coatings, strong crystal form, and the rare combination of structural precision with vibrant, naturally formed iridescence.