Assertion: beryl's form | /r/CapableOf | allow perfect cleavage
Facets:
value: into very thin leaves
type: TRANSITIVE-OBJECT
Source sentences:
text: isinglass, mica any of various minerals consisting of hydrous silicates of aluminum or potassium etc. that crystallize in forms that allow perfect cleavage into very thin leaves; used as dielectrics because of their resistance to electricity