When I was young!!!. Metamorphic rocks are formed from other rocks Which are changed by heat and pressure. Metamorphic Rocks generated by recrystallization of either igneous or sedimentary rocks by the action of any or all of the following: Pressure Temperature Mineral Rich Fluids
Which are changed by heat and pressure
Growth of new minerals
Deformation and rotation of mineral grains
Recrystallization of minerals as larger grains
generated mainly by temperature at the margins of igneous intrusions..
Texture - granular.
Grain size - medium grained; can see interlocking quartz crystals with the naked eye.
Hardness - hard.
Colour - variable - pure quartzite is white but quartzite exists in a wide variety of colours.
Mineralogy - quartz.
Other features - generally gritty to touch.
d-regional metamorphic e-igneous rock