Halides form the third class of the Strunz mineral classification. They are characterized by compounds in which halogens such as fluorine, chlorine, bromine or iodine play an essential role in the chemical composition. In addition to simple halides, the class also includes more complex compounds as well as oxyhalides and hydroxyhalides.

Among the best-known representatives are fluorite, halite, sylvite, carnallite, cryolite, villiaumite and atacamite. Halide minerals can form in a wide range of geological environments, including hydrothermal veins, evaporite deposits, alkaline igneous systems and oxidation zones of ore deposits.

Fluorite (CaF₂) is one of the best-known and most important halide minerals for collectors. It commonly occurs in hydrothermal veins and ore deposits and is especially valued for its wide range of colors and frequently well-developed crystals.

Halite and sylvite are typical minerals of evaporite deposits and form through the evaporation of saline waters. Cryolite, by contrast, is a much rarer fluorine-bearing mineral known mainly from highly specialized igneous environments. Atacamite, a copper-bearing hydroxychloride, forms especially under oxidizing conditions in arid climates and can develop intense green, acicular or radiating crystal aggregates.

The Mineralien Weltweit range includes halide minerals from different localities and geological environments. Each collector specimen is documented with precise locality information, dimensions, weight and original photographs.