- Fine-grained, dense sedimentary rock consisting of interlocking crystals of quartz approximately 30 microns in diameter. Chert and its varieties, such as flint, are non-gem varieties of cryptocrystalline-granular quartz. These stones chip very easily and thus may be fashioned into tools with a sharp edge; they are also used for building.
- Typically reserved to refer narrowly to the cultures of the native peoples of the United States and Canada, excluding the Eskimos and Aleuts. For the indigenous peoples of Canada use the term "First Nations." For the broader concept of the cultures of any native peoples of Central America, South America, North America, or the West Indies who are considered to belong to the Mongoloid division of the human species, use "Amerindian (culture)."
- Refers to the cultures of the continent of North America, which is bounded by the Atlantic Ocean, the Pacific Ocean, the Arctic Circle, and Central America. In classifications schemes based on physical geography, Central America, and North America are parts of the same continent.
- Pieces of hard material, typically stone or metal, sharpened to have a cutting edge or penetrating point for use as projectiles or the heads of projectile weapons.
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