What is an index mineral example?
What is an index mineral example?
A mineral that forms only under specific pressure and temperature conditions, and that therefore provides information about the metamorphic history of the rock in which it is found. The minerals kyanite, andalusite, and sillimanite are examples of index minerals.
What are some low grade minerals?
Typical low-grade metamorphic minerals are albite, muscovite, chlorite, actinolite and talc.
What do index minerals indicate?
Index minerals in metamorphic rocks indicate how much the original rock was metamorphosed, called the grade of metamorphism. Index Minerals minerals include chlorite, epidote, garnet, staurolite, kyanite and sillimanite.
Why is quartz not a good index mineral?
Is quartz a good index mineral of metamorphic grade? Why or why not? No because they tend to crystallize in low grade as well as high grade conditions, they are ubiquitous. They do indicate a specific metamorphic condition and are not considered index minerals.
Is quartz an index mineral?
Note Quartz and Feldspar are not index minerals: Why? 2. the reactions of minerals with fluids (for example salty or alkaline water) at high temperatures and pressures.
Is biotite an index mineral?
These index minerals also provide important clues to a rock’s sedimentary protolith and the metamorphic conditions that created it. Chlorite, muscovite, biotite, garnet, and staurolite are index minerals representing a respective sequence of low-to-high grade rock.
Is marble high or low grade?
Marble is a high-grade metamorphic rock, meaning that the pressure and temperature combination required to change limestone into marble is very high….
What is the order of index minerals from low grade to high grade metamorphism?
Slate. What is the order of index mineral appearance from low grade to high grade metamorphism? Chlorite, biotite, muscovite, garnet, staurolite, sillimanite.
What is an index mineral quizlet?
what is an index mineral? it is a mineral found in a metamorphic rock that is diagnostic of the pressure and temperature at which the rock was metamorphosed.
Is feldspar an index mineral?
Index Minerals in metamorphic rocks Note Quartz and Feldspar are not index minerals: Why? 2. the reactions of minerals with fluids (for example salty or alkaline water) at high temperatures and pressures.
What minerals form Porphyroblasts?
Garnet commonly forms porphyroblasts. It is a silicate mineral which is often used in gemstones.
Is amphibole an index mineral?
Amphibolite
| Type | Metamorphic Rock |
|---|---|
| Index Minerals | Amphibole |
| Color | Black |
| Miscellaneous | Salt and pepper appearance |
| Metamorphic Type | Regional |