Rocks for Dummies
Rocks are composed of minerals.Minerals are inorganic substances with a definite chemical composition.They may also be inorganic which are formed by living organisms.Rocks are classified by their origin. There are three types of rocks.
- Are found in (intrusive) or outside of (extrusive) volcanoes
- Are formed by melting and solidification (cooling)
- It's texture consists of a glassy surface,Inter connected crystals,and vesicles (holes).
- Are found deep below the earth's surface
- Are formed by intense heat and pressure
- It's texture consists of foliation (bands) or non-foliation.
- Its an intrusive Rock
- Its crystal size is 10 mm and up
- Its texture is very coarse and non-vesicular
- Compact and may easily split
- Its composition is mostly quartz,feldspar,and clay minerals;may contain fragments of other rocks and minerals
- Its grain size is clay (less than 0.0004 cm)
- Its texture consists of clastic (fragmental)
The Rock Cycle
The rock cycle is a model showing the relationship as to how rocks and sediments change over time.