Halides

HalidesHalidesare a group of minerals whose principle anions arehalogens.are a special group of elements that usually have a charge of negative one when chemically combined.tend to have rather simply ordered structures and therefore a high degree of symmetryHalide MineralsHaliteSylviteChlorargyriteBromargyriteFluoriteCryoliteCarnalliteAtacamiteBoleiteHaliteNaCl (Sodium chloride)System: IsometricHardness: 2.5Luster: VitreousCrystal form: CubicSpecific Gravity: 2.2Distinct property : Salty tasteRarity: Very CommonEnvironment: Saline lakesUses: Vital ingredient in human and animal dietHalite

SylviteKCl (Potassium Chloride)System: IsometricHardness: 2Luster: VitreousCrystal form: CubicSpecific gravity: 1.99Rarity: Very rareEnvironment: Sedimentary evaporite deposits associated with haliteUses: Industrial mineral used as fertilizerSylvite

ChlorargyriteAgCl (Silver Chloride)System: IsometricHardness: 1 1.5Luster: Submetallic lusterCrystal form: CubicSpecific gravity: 5.5 5.6Rarity: Very rareEnvironment: Alteration product from chlorine-rich solutionsUses: Silver-rich mineralChlorargyrite

BromargyriteAgBr (Silver Bromide)System: IsometricHardness: 1.5 -2Luster: GreasyCrystal form: CubicSpecific gravity: 5.8 6Rarity: Very rareEnvironment: Oxidized portions of silver deposits.Uses: Silver- rich mineralsBromargyrite

FluoriteCaF2 (Calcium fluoride)System: IsometricHardness: 4Luster: VitreousCrystal form: DodecahedronSpecific gravity: 3.1 3.3Rarity: Very commonDistinct property: Strong FluorescentEnvironment: High-temperature hydrothermal veins associated with leadUses: Production of Hydrofluoric acid

Fluorite

CryoliteNa3AlF6 (Sodium aluminum fluoride)System: MonoclinicHardness: 2.5Luster: Pearly or vitreousCrystal form: Pseudo-Cubic Specific gravity: 2.95 3.0Rarity: Very rareEnvironment: Occurs in pegmatites where it is probably precipitated by fluoride-rich solutionsUses: Flux in refining Bauxite. Insecticide and PesticidesCryolite

CarnalliteKMgCl3 * 6H2O (Hydrated potassium magnesium chlorideSystem: OrthorhombicHardness: 2.5Luster: Greasy Crystal form: pseudo-hexagonalSpecific gravity: 1.6Rarity: RareEnvironment: One of the last minerals to precipitate in an evaporite depositsUses: Potassium fertilizerCarnallite

AtacamiteCu2Cl(OH)3 (Hydrous copper chloride)System: OthorhombicHardness: 3 3.5Luster: VitreousCrystal form: PrismaticSpecific gravity: 3.76Rarity: RareEnvironment: alteration product of copper sulfide in surface oxidation zone as in desert conditionUses: secondary copper mineralAtacamite

BoleitePb9Ag3Cu8Cl21 (OH)16*H2O (Hydrated lead copper chloride)System: TetragonalHardness: 3.5Luster: VitreousCrystal form: Pseudo-cubic Specific gravity: 5.05Rarity: Very rareEnvironment: Surface alteration mineral in sulfide deposits generally in residual clays in the leached zoneUses: Purely of scientific interest; highly prizedBoleite