What are the agents that change rocks through metamorphism?

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1. What are the agents that change rocks through metamorphism?
2. What are the two textural divisions of metamorphic rocks and the conditions associated with each?
3. Distinguish between slaty (rock) cleavage, shistosity, and gneissic textures.
4. Briefly describe the three mechanisms by which minerals develop a preferred orientation.
5. Andalusite, garnet and sillimanite are metamorphic index minerals – what metamorphic conditions (grade) do each “index”?
6. What is the connection between shale, slate, phyllite, schist and gneiss?