Earth Science Flashcards

Which of the following comparisons of rocks and minerals is accurate?

Answer: Rocks are classified by their formation and the minerals they contain, while minerals are classified by their chemical composition and physical properties.

Explanation: Minerals are categorized according to their chemical makeup and physical characteristics, whereas rocks are classified according to their formation and their minerals.

Which of the following statements most accurately describes mineraloids?

Answer: Mineraloids are similar to minerals, but they lack a crystalline structure

Explanation: Mineral-like compounds without a crystalline structure are known as mineraloids. They are frequently discovered in rocks. Polymorphs are inorganic solids that contain two or more minerals with dissimilar crystalline structures.

The following are all subfields of petrology, EXCEPT:

Answer: Mineralogical petrology

Explanation: Petrology does not include the field of mineralogical petrology. The different types of rocks, such as metamorphic, igneous, and sedimentary, are studied by petrologists. The geochemistry of materials exposed to high temperatures and pressures is also reviewed by some petrologists, known as experimental petrologists. Petrologists do not look at minerals; mineralogists do.

Which of the following is NOT one of the minerals' five main physical characteristics?

Answer: Chemical composition

Explanation: Chemical composition is not a physical characteristic that is used to categorize minerals. Luster, hardness, cleavage, streak, and shape are the five main physical characteristics used to classify minerals. The chemical makeup of minerals has led to a different classification scheme.

In the Mohs scale, which of these minerals would have the lowest rating?

Answer: Talc

Explanation: Talc is the softest mineral that can be measured using the Mohs scale (a one). The maximum score is 10, which is represented by the diamond. At the same time, the scores for fluorite and gypsum are two and four, respectively. Minerals may always scrape other minerals with a lower Mohs rating.

The real color of a mineral can be seen by:

Answer: Conducting a streak test on unglazed porcelain tile

Explanation: An unglazed porcelain tile is used for a streak test to determine a mineral's natural color. The paper does not have suitable physical characteristics for the streak test. Since streak tests can show a color different from the substance's exterior hue, external observation (examining the mineral's outer surface) is not enough to determine accurate color. Finally, color is not determined by the shine test.

Which of the following describes minerals with lusters, such as galena, pyrite, and magnetite?

Answer: Metallic

Explanation: Minerals with a metallic sheen include galena, pyrite, and magnetite. A mineral having a greasy luster is an opal, while diamonds have an adamantine brilliance. Minerals with a pearly sheen include muscovite and stilbite. There are additionally dull, smooth, waxy, and sub-metallic lusters.