LAB: 2-3 Igneous Rock Identification
Igneous: Produced under the conditions involving intense heat. Intrusive: Igneous rock that forms beneath Earth’s surface. Extrusive: Igneous rock that forms at the Earth Surface.
Felsic: Igneous rock rich in potassium feldspar and quartz and light color. Mafic: Igneous rocks that are rich in dark Plagioclase feldspar, pyroxene and that are dark in their color. Lava: Magma that reaches Earth surface.
Texture: The feel of a rock due to its size, shape and its arrangement of mineral crystal or sediment in a rock. Porphyry: Igneous rock containing coarse crystals in a finer grained groundmass
5| Light| Vesicular| Extrusive| | Felsic| Pumice|
6| Dark| Glassy| Extrusive| | Felsic| Obsidian|
7| Light| VeryCoarse| Intrusive| | Felsic| Pegmatite| 8| Light| Fine| Extrusive| | Felsic| Rhyolite|
9| Dark| Fine| Extrusive| | Mafic| Basalt|
10| Dark| Vesicular| Extrusive| | Mafic| VesicularBasalt| 11| Light| Non-Vesicular| Intrusive| | Felsic| Pegmatite| 12| Light| Coarse| Intrusive| | Felsic| Granite|
Sample #| Color(Light orDark)| Texture| How Formed( Extrusive OR Intrusive)| MineralsPresent| Composition(Felsic OR Mafic)| RockName| 1| Dark| Vesicular| Extrusive| Plagioclase Feldspar| Mafic| Scoria| 2| Light| Coarse| Intrusive| | Felsic| Granite|
3| Dark| Coarse| Intrusive| | Mafic| Gabbro|
4| Light| Coarse| Intrusive| | Felsic| Diorite|
1. The size of the mineral grains affected by the rate in which molten rock material cools is that if an igneous rock has large crystals it takes more time to cool and form crystals, but if the rock have very small crystals or no crystals it cools more quickly. 2. You can determine if an igneous rock has Extrusive...