Rocks & Minerals Test

ESRT-based • Study notes + practice • Version date: 2026-01-21

Universal routine (use every time)

Underline evidence → choose the ESRT chart → eliminate choices that don’t match → re-check that

the final choice matches ALL evidence. Constructed response = CER: Claim (1 sentence) + Evidence

(2 specific details) + Reasoning (science idea linking evidence to claim).

1) Mineral identification (ESRT mineral chart)

• Use 2–3 properties together: luster, streak, hardness, cleavage/fracture, density, magnetism,

acid reaction.

• Hardness tools (common): fingernail ~2.5, copper penny ~3.5, glass ~5.5, steel nail ~6.5.

Translate scratch results into a range.

• Acid reaction: fizzing indicates carbonates; powdered samples may react more clearly than a

fresh surface.

• Streak = powdered color; often more reliable than surface color. Cleavage breaks along flat

planes; fracture is irregular/curved.

Study move

Pick 6 minerals from ESRT. Make a mini-chart: Mineral name | 2 best ID properties | common

confusion mineral (and how to tell apart).

2) Igneous textures & cooling rate

• Coarse-grained = slow cooling (intrusive). Fine-grained = fast cooling (extrusive). Glassy =

extremely fast cooling. Vesicular = gas bubbles trapped in lava.

• Porphyritic = two-stage cooling (slow first, then fast). Large crystals formed first; fine

groundmass formed later.

• If the environment is near-surface (lava, seawater), expect faster cooling and smaller

crystals.

3) Igneous rock ID (ESRT igneous chart)

• Combine composition (felsic/intermediate/mafic/ultramafic) + texture

(coarse/fine/glassy/vesicular) to name the rock.

• Intrusive–extrusive pairs share composition but differ in texture (slow vs fast cooling).

• Composition clues: felsic = light-colored, high silica; mafic = darker, more Fe/Mg; ultramafic

= very Mg/Fe rich.

4) Sedimentary rocks (NEW — required for this test)

• Sedimentary rocks form from sediments by: weathering → erosion/transport → deposition →

compaction & cementation (clastic), OR by precipitation/organic accumulation

(chemical/organic).

• Clastic sedimentary rocks are classified by particle size: gravel (conglomerate/breccia), sand

(sandstone), silt (siltstone), clay (shale).

• Clues for deposition environment: rounded grains = longer transport; angular grains = little

transport; well-sorted = steady energy; poorly sorted = variable energy.

• Sedimentary structures (common evidence): fossils, ripple marks, cross-bedding, mud cracks,

layered bedding/strata.

Study move (sedimentary)

Practice describing a sedimentary rock in ONE sentence using: grain size + sorting/roundness +

one structure (ex: fossils/ripples) → infer energy of environment.

Rocks & Minerals Test — Review Sheet (Page 2)

ESRT-based • Study notes + practice • Version date: 2026-01-21

5) Metamorphism & rock fabric evidence

• Contact metamorphism: heat near intrusion; local baked zone. Regional metamorphism: heat +

pressure over large area; often foliation.

• Foliation evidence: aligned minerals, banding, stretched grains, repeated light/dark layers.

• Metamorphic products depend on parent rock type (ex: carbonate parent rocks behave differently

than shale or sandstone).

6) Relative dating in cross sections

• Superposition: lower layers are older (if not overturned).

• Cross-cutting: faults/intrusions are younger than rocks they cut.

• Contact metamorphism: baked zone means intrusion happened after surrounding rock formed.

• Write events oldest → youngest and justify each with a rule.

7) Bowen’s Reaction Series & magma evolution

• High-temperature minerals crystallize first; low-temperature minerals crystallize last.

• Fractional crystallization: removing early crystals changes the remaining melt over time.

• Mineral evidence: olivine/pyroxene → hotter/mafic; quartz/K-feldspar → cooler/later-stage.

• Graphing crystallization ranges: bars must match the given temperature intervals and be shaded

as directed.

3-sentence explanation to memorize

1) Early minerals form first at high temperature. 2) If they settle out, the remaining melt

changes composition. 3) Later minerals form from the evolved (changed) melt at lower

temperatures.

8) Fossils & correlation

• Use shared fossils as time markers to align outcrops even if rock types differ.

• Within each outcrop, use superposition to find oldest → youngest.

• After aligning, read the combined fossil order from oldest → youngest.

9) Rock cycle & volcanic deposits (claim–evidence)

• Surface → sedimentary: weathering → erosion/transport → deposition → compaction & cementation.

• Internal: heat/pressure (metamorphism) and melting/solidification (igneous).

• Layered ash/debris = evidence of particle deposition; use 2 specific passage details as

evidence in CER responses.

CER checklist

Claim = direct answer. Evidence = 2 specific details from passage/figure/data. Reasoning = rock

cycle / cooling rate / mineral ID idea explaining why evidence supports claim.

What Notes Should Be in Your Notebook (Study This)

Use this page like a checklist of note sections. If you cannot explain one bullet out loud, add

it to your notes and practice with the ESRT.

A. Minerals — must know vocabulary

• Luster (metallic/nonmetallic), streak, hardness, cleavage (planes) vs fracture (irregular),

density, magnetism, acid reaction.

• How to report hardness using scratch tests (ex: 'scratched by steel nail but not by glass'

implies a range).

• Carbonate minerals: why acids react (chemical reasoning: carbonate + acid releases gas).

B. Sedimentary — must know steps + classification

• Weathering vs erosion vs deposition (define each in your own words).

• Clastic size categories and rock names (gravel/sand/silt/clay →

conglomerate/breccia/sandstone/siltstone/shale).

• Sorting & roundness: what each indicates about transport distance and energy.

• Common structures: fossils, ripples, cross-bedding, mud cracks — what each suggests about

environment.

C. Igneous — must know texture words

• Intrusive vs extrusive: where they form; why cooling rate changes texture.

• Texture words: coarse, fine, glassy, vesicular, porphyritic (define and explain how each forms).

• Composition: felsic/intermediate/mafic/ultramafic (typical mineral groups; color trend).

D. Metamorphic — must know processes

• Contact vs regional metamorphism: heat vs pressure differences; what foliation means.

• Parent rock concept: how original rock type influences metamorphic product.

• Evidence of metamorphism in a photo/diagram (banding/alignment).

E. Geologic history — must know rules

• Superposition, cross-cutting relationships, and contact metamorphism as dating evidence.

• How fossils are used for correlation across outcrops (index fossil idea).