Cleavage: Cleavage Refers to some mineral's tendency to interrupt along particular planes of weak point. Gypsum reveals excellent cleavage in a single direction and good cleavage in another course. This allows it to interrupt into predictable flat or slightly angled pieces. Agates: A sort of quartz that varieties in volcanic https://www.propanraya.com/id/produk/eco-gypsum-ee-4050