Many minerals form beautiful crystals, but the most prized of all are gemstones. Uncut gems often look fairly ordinary–like rocks. It's only when they are cut and polished that they obtain the ...

Geodes, for instance, are created when mineral-rich water seeps into hollow spaces within rock formations and slowly evaporates, leaving behind dazzling crystals like quartz and amethyst.

An image of the rock shows crushed material with yellow crystals, like a geode that’s been smooshed. If you’re reaching to pinch your nose against the rotten-egg smell, don’t worry.

It is also illegal to remove rocks from West Virginia Wildlife ... calcite or dolomite crystals or iron minerals like pyrite—commonly known as fools gold—and siderite. In some areas of ...

This reliquary holds a bone fragment purportedly belonging to Saint Sebastian, within a central rock-crystal vessel. Reliquaries—containers constructed to hold relics, typically the bones of saints or ...

Celestite crystals from Morocco. Burning calcium, sodium and cadmium will produce yellow light. Named after the Latin word for lime, calcium is very common in limestone rocks composed of calcite ...