Crystalline frost

From Glossary of Meteorology

crystalline frost

Hoarfrost that exhibits a relatively simple macroscopic crystalline structure; to be distinguished from amorphous frost.

Crystalline frosts are classified into five forms: 1) needle; 2) featherlike; 3) plate; 4) cup; and 5) dendritic. Such ice forms are typically developed as a result of deposition at temperatures well below 0°C, the degree of supersaturation and temperature controlling the form.

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