1) a) Allophane is naturally occurring, Si and Al rich amorphous (no long-range
ID: 154679 • Letter: 1
Question
1) a) Allophane is naturally occurring, Si and Al rich amorphous (no long-range order) material that forms from the chemical weathering of feldspars. Based on the definition of a mineral, is allophane is a mineral or a mineraloid? Explain your answer. b) Wadsleyite (Mg,Fe) 2SiO4 is thought to be an important mineral in Earth's mantle between about 410 km depth and 520 km depth. Samples from this depth have never been recovered with wadsleyite, but wadsleyite was discovered in 1979 in a shocked meteorite called Peace River (Putnis, 1979). Is Wadsleyite a mineral? Explain your answer. c) In the formula for wadsleyite (Mg,Fe) 2SiO4 , what does (Mg,Fe) indicate?Explanation / Answer
a) A mineraloid is a mineral-like substance that does not demonstrate crystallinity. Allophane is a mineraloid since it has short-range atomic order and is amophous.
b) A mineral is a naturally occurring substance that is solid and inorganic representable by a chemical formula so it is a mineral.
c)this indicate presence of both the metal whose compositin may vary from sample to sample
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.