Quartz
Nickel does not exhibit cleavage as it is a metal and lacks the crystalline structure necessary for cleavage. Instead, metals like nickel tend to deform plastically under stress rather than breaking along well-defined cleavage planes.
the cleavage of gold is hackly. gold has niether fracture or cleaveage
Opal does not have a cleavage or fracture because it lacks a distinct cleavage plane like minerals such as mica or calcite. Instead, opal typically fractures conchoidally, meaning it breaks with smooth, curved surfaces similar to glass.
Quartz lacks cleavage because it does not have any preferred planes of weakness along which it can split. It has a crystalline structure with equally strong bonds in all directions, making it fracture along irregular surfaces instead of cleaving in a predictable manner.
Cleavage is the way a mineral breaks along planes of weakness in its atomic structure. The number and orientation of cleavage planes are determined by the arrangement of atoms in the mineral's crystal lattice. Minerals with strong atomic bonds tend to have poor or no cleavage, while those with weaker bonds exhibit good cleavage.
Quartz
Yes. Quartz can have very well-formed crystals but lacks cleavage.
Nickel does not exhibit cleavage as it is a metal and lacks the crystalline structure necessary for cleavage. Instead, metals like nickel tend to deform plastically under stress rather than breaking along well-defined cleavage planes.
Sulfur does not exhibit cleavage because it lacks a distinct crystal structure. Instead, sulfur has a conchoidal fracture, meaning it breaks along curved, irregular surfaces similar to glass.
the cleavage of gold is hackly. gold has niether fracture or cleaveage
Opal does not have a cleavage or fracture because it lacks a distinct cleavage plane like minerals such as mica or calcite. Instead, opal typically fractures conchoidally, meaning it breaks with smooth, curved surfaces similar to glass.
NONMETAL
Beryllium does not exhibit cleavage because it lacks planes of weakness along which it can split cleanly. Instead, beryllium tends to fracture in a conchoidal or irregular pattern when subjected to stress.
Quartz does not have cleavage because it lacks planes of weakness along which it breaks. Instead, quartz exhibits conchoidal fracture, breaking in a way that produces curved, shell-like pieces.
Cleavage in two directions, one good, one distinct.
nonmetals
The verb...which your question lacks!