Granulite is a high-grade metamorphic rock, belonging to the granulite facies, that forms under extreme heat and pressure within the Earth’s crust. This rock exhibits a medium to coarse-grained texture and is typically composed of light-colored minerals, such as feldspar and quartz, which give it a granitic appearance. Granulite can be found in various shades of gray, pink, or even green, depending on its mineral composition. Due to its high strength and resistance to weathering, granulite is often used as a building material and for decorative purposes.
Mineral Makeup
The mineral makeup of granulite is predominantly composed of feldspar and quartz, with varying amounts of other minerals such as biotite, garnet, amphibole, pyroxene, and sillimanite. The specific mineral composition of granulite varies depending on the protolith (parent rock) and the metamorphic conditions it has experienced.
Origin
Granulite forms from the metamorphism of various types of rocks, such as sedimentary, igneous, or lower-grade metamorphic rocks, under high temperature and pressure conditions. This metamorphism typically occurs at depths of 20-40 kilometers within the Earth’s crust, where the rock is subjected to extreme heat and pressure during tectonic events, such as continental collision or subduction.
Occurrence
Granulite can be found in several regions worldwide, often associated with ancient mountain-building events. Some notable occurrences of granulite include the Canadian Shield, the Eastern Ghats of India, the Limpopo Belt in southern Africa, and the Bohemian Massif in central Europe.
Metaphysical
Granulite is believed to possess several metaphysical properties, including stability, clarity, and transformation. It is thought to help individuals find balance in their lives and maintain a clear, focused mind during times of change or personal growth. Granulite is also said to support the process of transformation, allowing one to let go of old patterns and embrace new opportunities with confidence and courage.
| Class | Metamorphic (Non-foliated) |
| Mineral Makeup | Primarily feldspar and quartz, with possible biotite, garnet, amphibole, pyroxene, and sillimanite |
| Luster | Vitreous to slightly dull |
| Hardness (Mohs) | 6-7 |
| Streak | White or colorless |
| Color | Gray, pink, or green, depending on mineral composition |
| Cleavage | Variable, depending on mineral composition |
| Specific Gravity | 2.6 to 3.0, depending on mineral composition |
