Definition

1. Noun:
   • A type of mineral: Agate is an impure, microcrystalline form of the mineral quartz. It is characterized by its fine, colorful bands or layers, which are typically curved or parallel.
   • A gemstone: Due to its varied and often beautiful patterns, agate is commonly cut and polished for use as a decorative gemstone in jewelry and ornamental objects.
   • A material for tools: Historically, because of its hardness and durability, agate has been used to make mortars and pestles for grinding substances.

Examples of Usage

• Noun:
  • She wore a beautiful necklace with an agate pendant.
  • The museum displayed a collection of polished agates from around the world.
  • Ancient chemists used an agate mortar to grind pigments.

Advanced Usage

• "Moss agate": A specific variety of agate that contains mineral inclusions resembling moss or trees.

  • The ring featured a stunning piece of moss agate.

• "Agate line": In historical U.S. printing and advertising, a unit of measurement for column space in newspapers, named after the 5.5-point type size once called "agate."

  • The advertisement was sold by the agate line.

Variants and Related Words

• Chalcedony (n): A broader category of microcrystalline quartz that includes agate, onyx, and other similar stones.
• Onyx (n): A type of chalcedony with parallel bands, often black and white, closely related to agate.

Synonyms

• Banded chalcedony: A technical synonym describing its structure.
• Semi-precious stone: A general category that includes agate.

Related Phrases

(Note: As a noun for a stone, "agate" does not form standard phrasal verbs. The related term "agate line" is covered in Advanced Usage.)

Related Idioms

(Note: There are no common idioms directly centered on the word "agate.")

Noun

1. an impure form of quartz consisting of banded chalcedony; used as a gemstone and for making mortars and pestles