Scoria is an extrusive igneous rock characterized by its vesicular or porous texture, which results from the release of volcanic gases during the rock’s formation. The rock’s class is typically basaltic, andesitic, or intermediate, and it is commonly dark gray, black, red, or brown in color. Scoria’s rough, porous surface and lightweight nature make it a popular choice for landscaping and decorative purposes, as well as for use in construction projects.
Mineral Makeup
The mineral composition of scoria primarily consists of plagioclase feldspar and pyroxene, with possible traces of olivine, amphibole, or other minerals depending on the specific lava flow. Plagioclase feldspar is typically light to dark gray or white, and in scoria, it may appear as tiny, elongated crystals. Pyroxene, a group of dark-colored minerals, can be found in scoria as small, needle-like crystals, while olivine, if present, appears as small, rounded grains.
Origin
Scoria forms during volcanic eruptions when lava containing dissolved gases is ejected into the air. As the lava cools rapidly, the gases escape, leaving behind a network of pores and cavities in the rock. This process results in scoria’s characteristic vesicular texture, which distinguishes it from other igneous rocks.
Occurrence
Scoria can be found in numerous volcanic regions across the globe, particularly in areas with basaltic or andesitic lava flows. Notable occurrences of scoria include the volcanic fields of Iceland, the Canary Islands, the Deccan Traps in India, and the volcanic landscapes of the western United States, such as Craters of the Moon National Monument in Idaho and various cinder cones in the Cascade Range.
Metaphysical
Scoria is believed to possess several metaphysical properties, including grounding, protection, and strength. It is thought to help individuals connect with the Earth’s energy, providing a sense of stability and support during challenging times. Scoria is also said to promote courage and perseverance, enabling individuals to overcome obstacles and face difficult situations with determination and resilience.
| Class | Igneous (Extrusive) |
| Mineral Makeup | Primarily plagioclase feldspar and pyroxene, with possible olivine, amphibole |
| Luster | Dull to vitreous |
| Hardness (Mohs) | 5-6 |
| Streak | White or colorless |
| Color | Dark gray, black, red, or brown |
| Cleavage | Imperfect to good |
| Specific Gravity | 1.0 to 2.0 |
