Earth Science Quiz: Rock And Mineral Id Tables

What this quiz covers

This quiz focuses on Rock And Mineral Id Tables, giving you a quick way to practice the rules, question types, and explanations that matter most for Earth Science.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. Sandstone and Quartzite (correct answer)
2. Limestone and Marble
3. Shale and Gneiss
4. Granite and Rhyolite

Explanation: Both Sandstone (sedimentary) and Quartzite (metamorphic) are composed primarily of Quartz. Table 2 specifically notes that Quartzite forms from the 'Metamorphism of sandstone.' While Limestone and Marble also share Calcite composition, the question asks for sedimentary-metamorphic pairs, and Sandstone-Quartzite represents the clearest example of this relationship in the table.

Question 2

1. Pyrite
2. Hematite
3. Orthoclase
4. Olivine (correct answer)

Explanation: This is a multi-step problem. First, determine the hardness range. The mineral scratches Orthoclase (hardness 6.0) but not Quartz (hardness 7.0), so its hardness is between 6.0 and 7.0. Next, check the table for minerals in this range with the other specified properties. Pyrite has a metallic luster. Hematite has a hardness of 5.0-6.0. Orthoclase has a hardness of 6.0 and shows cleavage, not fracture. Olivine has a hardness of 6.5, a non-metallic luster, and conchoidal fracture, matching all criteria.

Question 3

1. Slow cooling of magma deep underground, allowing large crystals to form.
2. Compaction and cementation of fine-grained volcanic sediments.
3. Instantaneous cooling of lava on the surface, preventing crystal growth. (correct answer)
4. High-pressure metamorphism of a dark-colored sedimentary rock.

Explanation: A rock with a 'glassy' texture is identified as Obsidian in Table 2. The 'Formation / Characteristics' column for Obsidian states it is 'Extrusive; cooled instantly'. This extremely rapid, or instantaneous, cooling prevents the formation of mineral crystals, resulting in the glassy appearance. Slow cooling (A) produces coarse-grained rocks like Granite. Compaction (B) forms sedimentary rocks. Metamorphism (D) would create a crystalline metamorphic rock.

Question 4

1. The rock's mineral composition, which actually matches Basalt.
2. The rock's texture, as Rhyolite is fine-grained. (correct answer)
3. The rock's type, as it is metamorphic rather than igneous.
4. The presence of quartz, which is not found in igneous rocks.

Explanation: The described rock with coarse grains of quartz, feldspar, and biotite is Granite, according to Table 2. The student identified it as Rhyolite. Both Granite and Rhyolite share the same composition (quartz, feldspar, biotite). However, their textures are different. Granite is coarse-grained (phaneritic), while Rhyolite is fine-grained (aphanitic). Therefore, the student most likely misinterpreted the texture of the rock.

Question 5

1. Igneous
2. Sedimentary
3. Metamorphic
4. Bioclastic (correct answer)

Explanation: First, identify the mineral. Metallic luster, greenish-black streak, and hardness > 5.5 points to Pyrite (Hardness 6.0-6.5). Pyrite (FeS₂) is a sulfide mineral that can form in igneous, metamorphic, and some sedimentary environments. A bioclastic rock, such as the Limestone described in Table 2, is formed from the remains of living organisms (shells, etc.), which are primarily composed of calcite. It is the least likely rock type to contain significant amounts of hydrothermally-formed Pyrite.

Question 6

1. The rock formed from magma that cooled slowly deep within the Earth's crust.
2. The rock formed from lava that cooled quickly on the Earth's surface. (correct answer)
3. The rock formed from the compaction and cementation of volcanic ash.
4. The rock formed from intense heat and pressure applied to a pre-existing rock.

Explanation: First, the rock must be identified. A fine-grained igneous rock made of pyroxene and plagioclase feldspar is Basalt, according to Table 2. The 'Formation / Characteristics' column for Basalt states it is 'Extrusive; cooled quickly, often vesicular'. Extrusive rocks form from lava cooling on the surface. Slow cooling (A) creates coarse-grained rocks like granite. Compaction (C) forms sedimentary rocks. Heat and pressure (D) form metamorphic rocks.

Question 7

1. Gneiss
2. Shale
3. Quartzite (correct answer)
4. Granite

Explanation: First, identify the initial rock. A rock made of sand-sized grains cemented together is Sandstone, as per Table 2. The question then asks what rock Sandstone becomes after undergoing metamorphism (intense heat and pressure). The entry for Quartzite in Table 2 lists its formation as 'Metamorphism of sandstone'. Therefore, Sandstone will become Quartzite.

Question 8

1. Color is a primary diagnostic tool; its hardness is a more reliable property.
2. Color is often unreliable; its hardness of 7 is a more reliable property. (correct answer)
3. Color is always consistent; its non-metallic luster is more reliable.
4. Color is unreliable for all minerals; its white streak is less reliable than color.

Explanation: The fact that Quartz can be various colors indicates that color is not a consistent, diagnostic property for this mineral and is therefore unreliable for identification. The question asks for another, more reliable property from the table. Hardness is a very consistent physical property. For Quartz, its hardness is always 7. This makes it a much more reliable identification tool than its variable color. Luster (C) and streak (D) are also reliable, but hardness is a key distinguishing feature listed and a better answer than the incorrect statements in C and D.

Question 9

1. It is a source of lead (Pb) due to its high specific gravity.
2. It is a major ore of iron (Fe) because of its composition. (correct answer)
3. It is often mistaken for gold, giving it the name 'Fool's Gold'.
4. It is used in construction as a primary component of plaster.

Explanation: The properties described (metallic/earthy luster, hardness 5.0-6.0, red-brown streak) match Hematite in Table 1. The 'Composition / Notes' column for Hematite indicates its composition is Fe₂O₃ and that it is a 'Major iron ore'. Therefore, its primary economic use is as an ore of iron.

Question 10

1. Hardness, because Halite is significantly harder than Calcite.
2. Streak color, as one produces a colored streak while the other does not.
3. Reaction to acid, as Calcite fizzes and Halite does not. (correct answer)
4. Luster, because Halite has a metallic luster and Calcite has a non-metallic luster.

Explanation: According to Table 1, both Halite and Calcite have a non-metallic luster and a white streak, making these properties unhelpful for differentiation. Their hardness values are close (2.5 for Halite, 3.0 for Calcite), which can be difficult to distinguish accurately without proper tools. However, the 'Composition / Notes' column for Calcite explicitly states it 'Fizzes in acid,' a unique chemical property not shared by Halite. This is the most definitive test listed.

Question 11

1. Marble, which forms from Limestone.
2. Quartzite, which forms from Sandstone.
3. Gneiss, which can form from Granite. (correct answer)
4. Basalt, which is an igneous rock.

Explanation: The description 'distinct banding of light and dark minerals' refers to a foliated texture, specifically the kind found in Gneiss. Table 2 confirms that Gneiss is a foliated (banded) metamorphic rock. The table also states that Gneiss can form from the 'high-grade regional metamorphism of granite or shale'. Since Granite is one of the options, this is a plausible parent rock. Marble (A) is non-foliated and would react with acid. Quartzite (B) is non-foliated. Basalt (D) is igneous, not metamorphic.

Question 12

1. Quartz
2. Olivine
3. Orthoclase (correct answer)
4. Pyrite

Explanation: The question asks which mineral can be ruled out. Let's check the given properties against the options. The mineral shows no cleavage (fracture). Orthoclase is listed as having '2 directions at 90°' cleavage, so it can be ruled out. Quartz has fracture and hardness 7. Olivine has fracture and hardness 6.5. Pyrite has fracture and hardness 6.0-6.5, but its streak is greenish-black, not white, so it can also be ruled out. However, Orthoclase is the best answer because the lack of cleavage is a direct contradiction. The student must use the process of elimination based on the most certain negative evidence.

Question 13

1. A: Quartz, B: Calcite
2. A: Pyrite, B: Hematite
3. A: Galena, B: Halite (correct answer)
4. A: Muscovite, B: Orthoclase

Explanation: The feeling of being 'heavier' for the same volume relates to the property of specific gravity or density. The question requires finding a pair of minerals where A has a significantly higher specific gravity than B. In Table 1, the 'Composition / Notes' column for Galena explicitly mentions 'High specific gravity'. Halite does not have this property and is known to have a low specific gravity. Therefore, Galena would feel much heavier than an equal-sized sample of Halite. The other pairs do not have such a pronounced and noted difference in specific gravity.

Question 14

1. Halite
2. Muscovite (correct answer)
3. Galena
4. Calcite

Explanation: The key property here is 'peeling off in thin, flexible sheets', which describes cleavage in one perfect direction. According to Table 1, Muscovite has '1 perfect direction (sheets)' of cleavage. Its hardness is 2.0-2.5, consistent with being scratched by a fingernail, and it has a non-metallic luster. Halite (A) has cubic cleavage. Galena (C) has a metallic luster. Calcite (D) has cleavage in 3 directions, not in sheets.

Question 15

1. Basalt
2. Sandstone
3. Marble
4. Granite (correct answer)

Explanation: The properties described (hardness 6.0, white streak, 2 cleavage directions at 90°) identify the mineral as Orthoclase, which is a type of feldspar, according to Table 1. The second step is to find a rock in Table 2 composed of feldspar and quartz. Table 2 shows that Granite has a composition of 'Quartz, Feldspar, Biotite'. Basalt (A) is composed of pyroxene and plagioclase feldspar. Sandstone (B) is mostly quartz. Marble (C) is made of calcite.

Question 16

1. Limestone and Marble
2. Shale and Gneiss
3. Granite and Rhyolite
4. Sandstone and Quartzite (correct answer)

Explanation: First, the mineral with hardness 7, non-metallic luster, and conchoidal fracture is identified as Quartz from Table 1. The second step is to find a sedimentary rock and a metamorphic rock in Table 2 that are composed mostly of Quartz. Sandstone is a clastic sedimentary rock listed as 'Mostly Quartz'. Quartzite is a non-foliated metamorphic rock listed with a composition of 'Quartz'. Therefore, Sandstone and Quartzite are the correct pair.

Question 17

1. The mineral will not scratch Calcite because it is softer. (correct answer)
2. The mineral will scratch Calcite because it is harder.
3. Neither mineral will scratch the other as they have the same hardness.
4. The outcome cannot be determined because the hardness of Calcite is variable.

Explanation: The mineral with cubic cleavage (3 directions at 90°), lead-gray streak, and metallic luster is Galena, according to Table 1. Galena's hardness is listed as 2.5. Calcite's hardness is listed as 3.0. Since Galena (2.5) is softer than Calcite (3.0), it will not be able to scratch Calcite. This requires a two-step process of identifying the unknown mineral and then comparing its hardness to a known mineral from the table.

Question 18

1. A hardness of 7 and conchoidal fracture.
2. A metallic luster and a lead-gray streak.
3. Cleavage in 3 directions not at 90° and a reaction to acid. (correct answer)
4. Perfect cleavage in one direction and a hardness of 2.0-2.5.

Explanation: This is a two-table question. First, find Marble in Table 2. Its composition is listed as Calcite. Second, find the properties of Calcite in Table 1. Calcite has a hardness of 3.0, cleavage in '3 directions, not at 90°', and it 'Fizzes in acid'. Option C matches these properties. Option A describes Quartz. Option B describes Galena. Option D describes Muscovite.

Question 19

1. A test for cleavage planes, to confirm it is fracture.
2. A streak test, to check for a red-brown or greenish-black color. (correct answer)
3. An acid test, to see if the mineral fizzes.
4. A taste test, to determine if the mineral is salty.

Explanation: The properties given (hardness 5.0-6.5, fracture) narrow the possibilities in Table 1 to Pyrite and Hematite. Pyrite has a hardness of 6.0-6.5 and a metallic luster. Hematite has a hardness of 5.0-6.0 and can have a metallic or earthy luster. Since the luster is ambiguous, another property must be used. Comparing the two, their streak colors are very different: Pyrite's is greenish-black, and Hematite's is red-brown. A streak test would therefore be the most useful diagnostic test to distinguish between them.

Question 20

1. Shale, from the weathering of feldspar into clay particles.
2. Limestone, from the precipitation of dissolved mineral components.
3. Sandstone, composed primarily of the resistant quartz grains. (correct answer)
4. Conglomerate, formed from the cementation of large rock fragments.

Explanation: This question models a part of the rock cycle. Granite is composed of quartz, feldspar, and biotite. During weathering, quartz is very resistant and remains as sand-sized grains, while feldspar often weathers into clay. The transported sediment would be rich in sand-sized quartz grains. According to Table 2, a clastic sedimentary rock composed of sand-sized quartz grains is Sandstone. Shale (A) forms from clay-sized particles. Limestone (B) has a chemical or biological origin. Conglomerate (D) would require much larger rock fragments than those produced by granite weathering.