A mineral within a metamorphic rock that can be used to provide a narrow constraint on the temperature and pressure of formation of the rock is termed a(n)____________.
A) thermineral
B) index mineral
C) mafic mineral
D) halide mineral

Question

Quizplus · Accepted Answer

Index minerals are minerals that are reliable indicators of the pressure and temperature conditions at which they formed. They are used to determine the metamorphic grade of a rock and can provide a narrow constraint on the conditions of formation. Therminerals and halide minerals are not common terms in geology, and mafic minerals are a group of minerals that are commonly found in igneous rocks, but not necessarily indicative of metamorphic conditions.

A Mineral Within a Metamorphic Rock That Can Be Used