Crystal & mineral guide
Granite
Felsic intrusive rock
Coarse felsic intrusive rock — continental crust cornerstone and dimension stone.
Identify Granite with RockScanAbout Granite
Granite is a phaneritic felsic rock with visible quartz and feldspar. Used globally as dimension stone and aggregate. Field ID uses interlocking coarse grains and quartz presence (vs syenite). Not a gem but essential geology reference for collectors and field workers.
Granite belongs in a crystal identifier workflow because photo cues — color zoning, crystal habit, and surface luster — combine with measurable traits like Mohs 6–7 (aggregate) and specific gravity 2.65–2.75. Use RockScan’s camera to get a first-pass ID, then confirm with the checklist below.
Granite properties
| Mohs hardness | 6–7 (aggregate) |
|---|---|
| Crystal system | Phaneritic aggregate |
| Luster | Vitreous (quartz/feldspar) |
| Color | Pink, gray, white speckled |
| Composition | Quartz + K-feldspar + plagioclase ± mica/amphibole |
| Formation | Slow cooling of silica-rich magma at depth |
| Occurrence | Worldwide continental crust |
| Specific gravity | 2.65–2.75 |
| Cleavage | None (rock) |
How to identify Granite
- Visible quartz grains essential
- Coarse interlocking crystals
- Harder than marble; no acid fizz
Collector notes
- Makes up much of the upper continental crust
- Rapakivi and graphic textures are specialty varieties
Value context: Dimension stone priced by color, consistency, and polish quality.
Granite FAQ
How do you identify Granite?
Granite (Felsic intrusive rock) is typically recognized by pink, gray, white speckled color, vitreous (quartz/feldspar) luster, Mohs hardness 6–7 (aggregate), and phaneritic aggregate crystal system. RockScan can suggest Granite from a photo and surface these checks on the result card.
What is Granite made of?
Granite composition: Quartz + K-feldspar + plagioclase ± mica/amphibole. It forms via slow cooling of silica-rich magma at depth and is found in Worldwide continental crust.
Is Granite valuable?
Dimension stone priced by color, consistency, and polish quality.
