Definition

Noun: A type of quartz mineral that is typically milky white or greyish in color and is characterized by being translucent to transparent. It is a cryptocrystalline variety of silica.

Usage

Calcedony is used as a specific geological and gemological term to refer to this form of quartz. It is often discussed in contexts of mineralogy, jewelry, and decorative stones. * The necklace was made from polished beads of blue calcedony. * Calcedony is commonly found in volcanic rocks.

Advanced Usage

• As a material descriptor: The term is used to specify the mineral composition of an object or artifact.
  • The ancient seal was carved from a single piece of calcedony.

Variants and Related Words

• Chalcedony: This is the more common modern spelling and is synonymous with "calcedony." "Calcedony" is an older variant.
• Agate: A variety of chalcedony/calcedony characterized by banded patterns.
• Onyx: A variety of chalcedony/calcedony with parallel banding, often black and white.
• Carnelian: A red to orange variety of chalcedony/calcedony.

Synonyms

• Chalcedony
• Cryptocrystalline quartz

Notes on Different Meanings

This word has a single, specific meaning as a type of quartz mineral. The spelling "calcedony" is an accepted but less frequent variant of "chalcedony."

Noun

1. a milky or greyish translucent to transparent quartz