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Full Description

Gabbro blocks are coarse-grained, of black color and contain numerous crystals, iridescence in yellowish-green and blue colors. Well atomized and polished: belong to 1 class of radioactivity (used in construction without any restrictions). According to its physical and mechanical characteristics guarantee the lifetime for at least 200 years.

Color. Black, dark green, sometimes spotted formation.

Structure. Entirely and uniformly crystalline, coarse-and medium-grained.

Texture. Solid, sometimes spotty, banded.

Bedding Form. Large laccoliths, lopoliths, sills and stems. It often occurs in laminated differentiated intrusive bodies containing rocks of basic and ultrabasic composition. In ophiolite bodies forms the tectonic plates.

Parting. Bedded, parallelepiped

Genesis. Intrusive rock formation.

Deposits. Occurred in various parts of the UK, North America (in the Adirondack Mountains) and along the coast of the Labrador Peninsula (Canada), South Africa, France, Scotland (United Kingdom) and others; large solid monoliths gabbro are known in the Urals, Ukraine, the Kola Peninsula, in the Caucasus, etc.

The Practical Importance. Gabbro sometimes contains concentrations of ore minerals, and in these cases can be used as an ore of copper, nickel and titanium. Often used as building and facing stones of high strength, for the outer and inner facing, mostly in the form of polished slabs and for preparation of crushed stone and stone road.

Variety. Anorthosites do not contain dark-colored minerals, norites – are composed of plagioclase, rhombic pyroxenes, troctolites – are composed of plagioclase and olivine. If olivine with pyroxene is present in gabbro, the rock formation is called olivine gabbro. Rich with plagioclase (85-90%) gabbro is named as gabbro anorthosite. Among them the most known are labradorites, plagioclases of which, have often beautiful bluish or greenish color change. Gabbro containing appreciable amounts of olivine (> 5%) is called olivine gabbro. If pyroxenes are practically absent, and the rock consists mainly of plagioclase and olivine, these are usually called gabbro troctolite.

Diagnostics. Differs from diorite by high content of dark-colored minerals and, consequently, darker coloring.