What does druse mean?
A druse is a hollow cavity within a rock that is lined with small crystals projecting inward from its walls, a phenomenon prized by mineralogists and collectors alike. When such cavities are filled with striking crystals — quartz, amethyst, calcite, or other minerals — they are often what people mean by geodes, though the term druse is the more technical one in geology. The word also appears in lapidary contexts: a stone cut to display an unbroken crust of tiny crystals is said to have a druse or drusy surface, a popular finish in jewelry design. Druses form when mineral-rich fluids seep into gas bubbles or fissures in volcanic or sedimentary rock, allowing crystals to grow slowly over long periods. While largely confined to scientific and trade usage, the term rewards anyone interested in how some of nature's most dazzling displays arise inside otherwise ordinary-looking stones.
nounA cavity or vug in a rock lined with small projecting crystals; also called a druse cavity. The term is used chiefly in mineralogy and geology.
- A hollow cavity in rock lined with inward-pointing crystals.
- (In lapidary use) A surface covered with small crystals, as in 'drusy quartz' jewelry.
"Splitting open the geode revealed a sparkling druse of amethyst lining its interior."
"The miner's hammer cracked the basalt to expose a druse glittering with calcite crystals."
"The pendant featured a slice of agate finished with a shimmering druse surface."
Standard plural; used when referring to multiple crystal-lined cavities or multiple drusy specimens.
"The limestone quarry yielded several small druses lined with dogtooth spar."
That glittering geode on your shelf is technically a druse — nature's own crystal-lined treasure chest.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of druse
The word druse entered English in the early 19th century from German 'Druse', the term German miners applied to crystal-lined cavities in rock. Its deeper origins are obscure, though it has been linked by some etymologists to mining dialect terms of Central Europe. It should not be confused with 'Druze', which refers to the Middle Eastern religious community and has an entirely separate Arabic-derived origin.
Related word forms
How druse is actually used
Primarily technical vocabulary used in mineralogy, geology, and gemology; rare in everyday speech. The adjective 'drusy' is common in the jewelry trade for crystal-encrusted stone surfaces. The plural is 'druses'.
Easily confused with druse
Druze (usually capitalized) refers to a member of a Middle Eastern monotheistic religious community, while druse refers to a crystal-lined cavity in rock.