Perlite typically displays fracture rather than cleavage. Its structure is composed of randomly arranged, glassy particles due to its volcanic origin, leading to a conchoidal fracture pattern when broken.
Perlite exhibits perfect cleavage in one direction, along the planes of its basal pinacoid. This results in smooth and flat surfaces when perlite is broken or cut.
the cleavage is Poor
Sapphire has a mixture of both cleavage and fracture characteristics. It has poor cleavage in one direction and conchoidal fracture, which means it breaks with smooth, curved surfaces similar to glass.
Quartz has a conchoidal fracture. It does not have a cleavage plane.
Silver has neither cleavage nor fracture because it is malleable and ductile, meaning it can be shaped and stretched without breaking along specific planes like cleavage or irregularly like fracture.
Perlite exhibits perfect cleavage in one direction, along the planes of its basal pinacoid. This results in smooth and flat surfaces when perlite is broken or cut.
Quartz does not have cleavage. However, it does have fracture. Its fracture is conchoidal.
it has no cleavage
it has no cleavage
cleavage
Fracture
Hematite has a characteristic fracture, meaning it breaks irregularly with rough or jagged edges and no smooth cleavage planes.
the cleavage is Poor
Sapphire has a mixture of both cleavage and fracture characteristics. It has poor cleavage in one direction and conchoidal fracture, which means it breaks with smooth, curved surfaces similar to glass.
It has both: uneven fracture, and perfect cleavage in three directions.
It has both cleavage and fracture.
Cleavage