Question

minerals with the same chemical composition, but different crystalline structure, are referred to as
duplicative
polysynths
polychems
polymorphs
metamorphs
question 5 (0.83 points)
at a depth of 15 km, and a temperature of 400 degrees c, the compound al₂sio₅ would form as the particular mineral (use textbook fig. 7.1.1) called:
kyanite
meta - sillimanite
meta - andalusite
sillimanite
meta - kyanite
aluminosilicate
andalusite

Explanation:

1. For the first question: The term describes minerals with identical chemical makeup but distinct crystal structures, which is a key definition in mineralogy.
2. For Question 5: Using the phase diagram for $\text{Al}_2\text{SiO}_5$, at 15 km (equivalent to ~4.5 kbar pressure) and 400°C, the stable polymorph is Kyanite.

Answer:

1. polymorphs
2. Kyanite