Rocks and Minerals Practice Tests
Free, AI-generated Rocks and Minerals practice tests for Science Olympiad. Choose Invitational, Regional, State, or National difficulty, import past exam PDFs, and track your scores over time.
Rocks and Minerals runs in both Division B and Division C for the 2027 season.
Try some questions · No sign-in required
Rocks and Minerals Sample Practice Questions
1. A mineral scratches glass but is scratched by quartz. Its Mohs hardness is most likely:
- 3 (calcite)
- 6 (orthoclase)
- 7 (quartz)
- 8 (topaz)
Show answer and explanation
Answer: 6 (orthoclase)
Glass is about 5.5 and quartz is 7, so the mineral must fall between them - hardness 6. Reference points: fingernail ~2.5, copper penny ~3.5, glass ~5.5, steel file ~6.5.
2. A mineral that breaks with smooth, curved, shell-like surfaces shows:
- Cleavage
- Conchoidal fracture
- Foliation
- Luster
Show answer and explanation
Answer: Conchoidal fracture
Conchoidal fracture (from "shell") breaks along curved surfaces with no preferred plane - classic in quartz and obsidian. Cleavage, by contrast, breaks on flat, repeated planes.
3. An intrusive igneous rock that cooled slowly deep underground, growing large crystals, is:
- Basalt
- Granite
- Obsidian
- Pumice
Show answer and explanation
Answer: Granite
Slow cooling lets crystals grow large and interlocking - granite. Basalt (extrusive) cools fast at the surface with fine grains; obsidian and pumice cool so fast they are glassy or bubbly.
4. A metamorphic rock with segregated light and dark mineral bands is:
- Marble
- Quartzite
- Gneiss
- Slate
Show answer and explanation
Answer: Gneiss
Gneissic banding forms under high-grade heat and pressure as light (feldspar/quartz) and dark (mica/amphibole) minerals separate into layers. Marble and quartzite are non-foliated; slate is low-grade foliated.
5. Hematite’s streak (powder color on a porcelain plate) is:
- Black
- Metallic silver
- Reddish-brown
- Colorless
Show answer and explanation
Answer: Reddish-brown
Streak is more reliable than surface color: hematite specimens can look metallic gray or red, but all leave a reddish-brown streak - it is the main ore of iron and the pigment in "red ochre."
Want the full timed version with scoring? Generate a free Rocks and Minerals practice test at Invitational, Regional, State, or National difficulty.
Indexed Rocks and Minerals Practice Tests by Difficulty
Reviewed full-length Rocks and Minerals practice tests, each with every question and answer choice listed on its own page.
What Rocks and Minerals Tests Cover
mineral identification, rock classification, rock cycle, and geological processes.
Mohs hardness scale (1-10)
1-Talc, 2-Gypsum, 3-Calcite, 4-Fluorite, 5-Apatite, 6-Orthoclase, 7-Quartz, 8-Topaz, 9-Corundum, 10-Diamond
- Fingernail ~2.5, Copper penny ~3.5, Glass ~5.5, Steel file ~6.5
Mineral properties
- Luster: Metallic vs Non-metallic (vitreous, pearly, silky, earthy, etc.)
- Cleavage: Breaks along flat planes (mica = 1 direction, halite = 3 at 90°)
- Fracture: Irregular break (quartz = conchoidal/shell-like)
- Streak: Color of powder (often different from mineral color)
- Specific gravity: Density relative to water
Rock types
- Igneous: From magma/lava. Intrusive (slow cooling, large crystals - granite) vs Extrusive (fast cooling, small/no crystals - basalt)
- Sedimentary: From weathering/deposition. Clastic (sandstone), Chemical (limestone from precipitation), Organic (coal)
- Metamorphic: Changed by heat/pressure. Foliated (slate, schist, gneiss) vs Non-foliated (marble, quartzite) COMMON MISTAKES: Confusing cleavage vs fracture. Mixing up intrusive vs extrusive igneous rocks.