Gabbro is an intrusive igneous rock, part of the plutonic class, primarily composed of plagioclase feldspar, pyroxene, and occasionally olivine. Its coarse-grained or phaneritic texture consists of visible mineral crystals, which are typically dark green or black in color. Gabbro is often found in oceanic crust and is the intrusive equivalent of basalt, its extrusive counterpart.
Mineral Makeup
The mineral composition of gabbro consists primarily of plagioclase feldspar, pyroxene, and sometimes olivine. Plagioclase feldspar is typically white to gray and forms elongated crystals, while pyroxene, a group of dark-colored minerals, usually appears as short, stubby crystals. Olivine, if present, is a greenish mineral found as small, rounded grains within gabbro.
Origin
Gabbro forms through the slow cooling and solidification of magma deep beneath the Earth’s surface. This slow cooling process allows for the formation of large, visible mineral crystals, resulting in the characteristic coarse-grained texture of gabbro. As an intrusive igneous rock, gabbro is typically found in large, underground masses called plutons.
Occurrence
Gabbro is predominantly found in oceanic crust, where it forms large intrusions called gabbroic complexes. Geographically, gabbro can be found in various locations worldwide, including the Troodos Ophiolite in Cyprus, the Shetland Ophiolite in Scotland, the Adirondack Mountains in New York, and the Duluth Complex in Minnesota.
Metaphysical
Gabbro is believed to possess metaphysical properties that promote grounding, balance, and protection. It is thought to help individuals connect with the Earth’s energies and provide a sense of stability during turbulent times. Gabbro is also said to enhance intuition, spiritual growth, and transformation, assisting in personal development and self-discovery.
| Class | Igneous (Intrusive) |
| Mineral Makeup | Primarily plagioclase feldspar, pyroxene, and sometimes olivine |
| Luster | Dull to vitreous |
| Hardness (Mohs) | 5-6 |
| Streak | White or colorless |
| Color | Dark green or black |
| Cleavage | Good to moderate |
| Specific Gravity | 2.8 to 3.3 |
