hoar crystal

hoar crystal

[′hȯr ‚krist·əl]
(hydrology)
An individual ice crystal in a deposit of hoarfrost; always grows by sublimation.
References in periodicals archive ?
5 Surface hoar crystals are large, loosely bound flakes.
The molecules rearrange themselves to form sugarlike granides, called depth hoar crystals, which are not cohesive--they don't stick together.
Another type of weak layer may form when sur ace hoar crystals, or frost, build up.