onyx marble
Noun: A hard, compact variety of calcite, often banded and used as a decorative stone.
"Onyx marble" is a specific geological and commercial term. It refers to a type of limestone (calcite) that is dense, can take a high polish, and frequently exhibits parallel bands of color. It is important to note that despite its name, it is not true marble (which is metamorphic) nor true onyx (which is a variety of quartz/chalcedony). It is used primarily for ornamental purposes, such as in carvings, tabletops, and interior decorative elements.
- The fireplace was faced with beautifully banded onyx marble.
- Ancient artisans frequently used onyx marble for intricate vases and small statues.
- The museum displayed a plaque made of green onyx marble.
- Geological Context: In geology and mineralogy, the term specifies a sedimentary rock composed primarily of calcite (calcium carbonate) deposited from cold-water solutions, often in caves (as a form of travertine).
- Commercial/Lapidary Context: In the decorative stone trade, "onyx marble" is valued for its translucency and vibrant bands, making it popular for lamps, tiles, and inlay work.
- Alabaster: A fine-grained, translucent form of gypsum (calcium sulfate), often confused with onyx marble but softer and chemically different.
- Calcite: The mineral form of calcium carbonate, of which onyx marble is a compact variety.
- Travertine: A form of limestone deposited by mineral springs, often porous; onyx marble is a denser, banded type of travertine.
- Banded calcite
- Mexican onyx (a common commercial name)
- Cave onyx
The term combines "onyx," referring to the characteristic bands, and "marble," referring to its polishable, stone-like quality. Its primary meaning is always tied to its composition (calcite) and physical structure (hard, compact, banded).
- a hard compact kind of calcite