How many cleavage directions does gypsum have?

How many cleavage directions does gypsum have?

Mineral Cleavage and Fracture Test Video

Mineral	Type of Breakage
	CLEAVAGE Cleavage in three directions at right angles (90o). Cubic cleavage.
Calcite
	CLEAVAGE Cleavage in three directions not at right angles (120o and 60o). Rhombohedral cleavage.
Gypsum

Does Gypsum have rhombohedral cleavage?

Selenite gypsum. Crystal variety that is colorless and transparent. Cleavage cleary seen here. Specimens like this could be confused with calcite, since it almost looks like this has rhombohedral cleavage.

What is the crystal shape of gypsum?

Gypsum sometimes forms in sandy areas, and crystals may trap sand inside when forming, causing a specimen to become brown or gray and opaque. These sand inclusions sometimes form hourglass formations in a crystal.

What is the luster of gypsum?

Gypsum is an evaporite mineral most commonly found in layered sedimentary deposits in association with halite, anhydrite, sulfur, calcite, and dolomite….

Physical Properties of Gypsum
Chemical Classification	Sulfate
Streak	White
Luster	Vitreous, silky, sugary
Diaphaneity	Transparent to translucent

Can you lick gypsum?

You can tell these minerals apart by licking both. Halite has a very salty taste and Gypsum doesn’t. Fear not, neither are toxic.

What are three gypsum names?

It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard/sidewalk chalk, and drywall….

Gypsum
Major varieties
Satin spar	Pearly, fibrous masses
Selenite	Transparent and bladed crystals
Alabaster	Fine-grained, slightly colored

Does gypsum cleave or fracture?

Cleavage/Fracture: Gypsum’s cleavage is complex, there is only good cleavage in one direction and fair in two others that create thin, rhombic fragments. Crystal Form: Gypsum appears mostly as a four sided crystal, otherwise known as tabular crystal.

https://www.youtube.com/watch?v=GkmZiXsB6UE