These shells occur at Hartlepool and Sunderland, where the rock assumes an oolitic and botryoidal character.
botryoidal and stalactitic masses are more common, or again the mineral may be compact and granular or loose and earthy.
It is never found as crystals, but always as encrusting and botryoidal masses with a microcrystalline structure.
Our decks became dry, and studded with botryoidal lumps of dirty foot-trodden ice.
At Arendal in Norway, the original locality for both the crystallized and botryoidal varieties, it is found in a bed of magnetite.
A fibrous variety with a botryoidal or globular surface is known as botryolite.