HALIDES Flashcards
NaCl
Halite
Isometric, with cubic habit; other forms rare. Some crystals hopper-shaped, meaning that the faces of the cube have grown more at the edges than in the center, giving the cube face a centrally depressed or hopper-shaped. form.
crystal form of halite
When the crystals or granular crystalline masses of halite showing cubic cleavage, known as _________. Also massive, granular to compact.
rock salt
What is the cleavage of halite?
Cubic {001} perfect
What is the hardness of halite?
2 1/2
What is the specific gravity of halite?
2.16
What is the color of halite?
Colorless or white, or when impure may show shades of yellow, blue, purple, and red.
Occurs most commonly in evaporite deposits, associated with gypsum, anhydrite, dolomite, and shale, in rock salt beds ranging in thickness from a few feet to several hundred feet.
Occurrence of halites
Valuable deposits are also found in intrusive masses known as ________, which have their roots in thick, bedded deposits.
salt domes
KCl
Sylvite
Isometric crystals with cube and octahedron frequently in combination. Usually in granular crystalline masses with good cubic cleavage; also compact.
crystal form of sylvite
What is the cleavage of sylvite?
Cubic {001} perfect
What is the hardness of sylvite?
2
What is the specific gravity of sylvite?
1.99
What is the usual color of sylvite?
Colorless to white; also shades of blue, yellow, or red caused by impurities.
T or F. Sylvite is salty, and more bitter than halite.
T
Has the same origin, mode of occurrence, and associations as halite but is much rarer.
Sylvite
CaF2
Flourite
Isometric, usually in cubes, and often in penetration twins. Other crystal forms are rare. Usually in crystals or in cleavable masses.
Crystal form of fluorite
What is the cleavage of fluorite?
Octahedral {111} perfect
What is the hardness of fluorite?
4
What is the specific gravity of flourite?
3.18
What is the usual color of fluorite?
Varies widely. Most commonly light green yellow, bluish green, or purple; also colorless, white, rose, blue, or brown.
A common, widely distributed mineral. In hydrothermal veins it may be the chief mineral, or it may be the gangue mineral in metallic ores, especially those of lead and silver. Also common in dolomites and limestones
Fluorite
