Word Wednesday: Drusy

Welcome to Word Wednesday, Wolfstone Rock Shop’s weekly look at the language of rocks, minerals, and gems.

Drusy—also commonly spelled druzy—describes a sparkling coating of very small crystals over a rock surface, cavity wall, or earlier mineral.

Why it sparkles

Many tiny crystal faces catch light at slightly different angles, creating a sugar-like shimmer. Drusy quartz is common, but calcite, dolomite, garnet, and other minerals can also form fine crystalline coatings.

A texture, not a mineral name

“Drusy” tells you about the size and arrangement of crystals, not their composition. Identification still requires properties such as hardness, luster, cleavage, reaction, associated minerals, and locality.

Collector tip

Fine drusy surfaces can trap dust and may be fragile. Begin with a soft air blower or brush and identify the mineral before using water or chemicals. Coated, dyed, or metal-vapor-treated drusy material is also sold, so ask about treatments.

See this texture and other mineral features in person at Wolfstone Rock Shop, 1857 N Casaloma Dr, Appleton, WI 54913. Inventory changes often, so call (920) 809-8577 if you are looking for a particular example.