chalcedony
Noun: A microcrystalline variety of quartz, typically appearing in a waxy luster and occurring in many forms and colors. It is often translucent to semi-translucent and is used as a gemstone and in ornamental objects.
"Chalcedony" is a specific geological and gemological term. It is used as a mass noun (uncountable) to refer to the material in general, but countable forms can refer to types or pieces of this material. * The artisan carved the intricate seal from a single piece of blue chalcedony. * Agate and onyx are both banded varieties of chalcedony. * The museum's collection includes several fine examples of Roman chalcedony.
- As a modifier: The term is often used attributively to describe other nouns.
- a chalcedony vase, chalcedony deposits
- In specialized contexts: The term is precise in geology, mineralogy, archaeology, and jewelry-making, distinguishing it from other forms of silica like jasper (opaque) or pure crystalline quartz.
- Agate (n): A variety of chalcedony characterized by concentric banding of colors.
- Onyx (n): A variety of chalcedony with parallel bands, often black and white.
- Carnelian (n): A red to reddish-brown variety of chalcedony.
- Chrysoprase (n): An apple-green variety of chalcedony colored by nickel.
- Sard (n): A brownish-red to brownish-orange variety of chalcedony.
- Microcrystalline (adj): Having crystals too small to be seen with the naked eye, a key characteristic of chalcedony.
- Microcrystalline quartz: The most precise technical synonym.
- Cryptocrystalline quartz: Another technical term emphasizing the hidden crystal structure.
The word "chalcedony" has a single, specific meaning in English, referring to this mineralogical group. It does not have different metaphorical or slang meanings. Its usage is consistently technical or related to gems and decorative arts.
- a milky or greyish translucent to transparent quartz