Granite
Granite is a coarse-grained igneous rock composed mainly of quartz, feldspar, and mica. It's one of the most common rocks in Earth's continental crust.
_1_(25435470626).jpg?width=760)
Granite properties at a glance
| Type | Igneous Rocks |
|---|---|
| Chemical formula | Variable mineral composition |
| Mohs hardness | 6.5 |
| Luster | vitreous |
| Streak | Variable; test individual minerals |
| Cleavage | Variable by mineral grains |
| Fracture | Uneven |
| Specific gravity | 2.7 |
| Transparency | opaque |
| Common colors | Pink, Gray, White, Black |
| Rarity | common |
Geology & background
Forms from slow cooling of silica-rich magma deep within Earth's crust.
Used in Egyptian pyramids and Roman structures.
How to identify Granite
- Check whether the specimen's color and texture match typical Granite examples.
- Photograph a fresh surface in natural light and avoid shadows, glare, or wet surfaces.
- Use hardness, streak, luster, grain size, and locality together; no single trait is enough for every specimen.
Where Granite is found
Granite is reported from multiple localities or geological settings. Exact locality should be verified from specimen provenance, maps, or field notes.
How much is Granite worth?
| Entry-level specimen | $1 |
|---|---|
| Typical collector specimen | $10 |
| Premium specimen | $50+ |
Value depends on size, condition, color, crystal quality, locality, rarity, preparation, and provenance. Treat this as educational guidance, not an appraisal.
Common uses
- Building stone
- Countertops
- Monuments
- Paving
Interesting facts
- Most abundant rock in Earth's continental crust
- The word comes from Latin 'granum' meaning grain
- Used in construction since ancient times
Care & safety
Treat Granite as a collector specimen unless hardness, cleavage, and fracture are confirmed.
Avoid inhaling dust. Do not cut, grind, or polish unknown specimens without eye protection and a properly rated respirator.
.jpg?width=320)
_3.jpg?width=320)
.jpg?width=320)