2) (5 points) A placer deposit or placer is an accumulation of minerals formed b

Question

2) (5 points) A placer deposit or placer is an accumulation of minerals formed by gravity separation during sedimentary processes. Minerals in placer deposits are dense and resi weathering. Valuable minerals often occurring in placer deposits are listed in the table belovw As an exploration geologist you will be expected to identify and sample potentially promising placer deposits. Basic mineralogy, especially crystallography, can help you. Consult the table in order to answer the following question. Your answer could name one mineral, several minerals, or none. With your hand lens you observe prismatic crystals terminating in four-sided pyramids. What mineral(s) can you eliminate from the list? Mineral Type Economic value Monazite Phosphate Rare earth elements and thorium monoclinic: 2/m Rutile Ilmenite Oxide Magnetite Oxide Iron Crystal system tetragonal; 4/m 2/m 2/m hexagonal (trigonal);3 isometric; 4/m 3 2/m tetragonal; 4/m 2/m 2/m isometric; 4/m 3 2/m tetragonal: 4/m 2/m 2/m monoclinic; 2/m Oxide Titanium Titanium Silicate Zirconium Zircon Chromite Oxide Chromium Cassiterite Oxide Wolframite Oxide Tungsten Tin

Explanation / Answer

For minerals that terminate in four sided pyramids, they should belong to the tetragonal crystal system that is Rutile, Zircon and Cassiterite. So the minerals which we can exclude/eliminate from the list are : Monazite, Ilmenite, Magnetite, Chromite and Wolframite.

Related Questions

Navigate

• Browse (All)
• Browse 2
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.