crystal

The word “crystal” means a solid substance whose atoms are arranged in a regular, repeating pattern, often forming clear geometric shapes. In plain terms, a clear, often geometrically shaped mineral or glass, or an adjective meaning very clear.

“Crystal” is pronounced KRIHS-tuhl (/ˈkɹɪstəl/ in IPA).

Here is “crystal” used in a sentence: “Snowflakes are made of tiny ice crystals.”

Words with a similar meaning to “crystal” include crystalline.

Depending on how it is used, “crystal” can be a noun and an adjective.

The word “crystal” comes from Greek. From Greek krystallos ("clear ice"), reflecting how ancient people once believed quartz crystal was permanently frozen ice.

“Crystal” is a fairly common word in modern English.

“Crystal” has 3 distinct senses listed in this dictionary. The most common is: a solid substance whose atoms are arranged in a regular, repeating pattern, often forming clear geometric shapes.

A mineral is a naturally occurring solid with a definite chemical make-up. A crystal is the form a solid takes when its atoms line up in a regular, repeating pattern, often producing clear geometric shapes. Many minerals are crystals, but crystals can also be man-made, such as grown quartz or salt.

Everyday examples include table salt, sugar, and snowflakes, all of which have orderly atomic patterns. Gemstones such as diamond, quartz, and amethyst are crystals too, prized for their geometric shapes and clarity. Even metals and many rocks are made of tiny crystals packed together.

Crystals form when atoms or molecules settle into a regular, repeating arrangement as a substance solidifies — as molten rock cools, as water evaporates from a salty solution, or as vapour freezes. Given time and stable conditions, this ordered growth produces the flat faces and geometric shapes crystals are known for.

Their clarity and sharp shapes come from the highly ordered way their atoms are stacked. Because the internal pattern repeats evenly in every direction, the outer surfaces grow as flat faces meeting at consistent angles, and light can pass cleanly through a well-formed, defect-free crystal, giving it a transparent appearance.