⚛️ Igneous Rocks & Volcanism — printable rubric packet (Geology Unit 02). Print 8.5×11 portrait. Every page is designed for clipboard use while you grade at the bench.
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▲ Page 1 — Unit overview
Bright Minds Geology · Course Pack
Igneous Rocks & Volcanism — Unit Packet
Overview
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Use these targets, vocabulary, rubrics, examples, and score sheet with the instructor's approved lesson and procedure. This is an assessment companion, not a complete lesson or safety authorization.

Student lessons, data, and worked answers: Unit 02 learning pathway.

Unit learning targets

The student demonstrates the following:

How this unit is assessed

Mastery rubric

Five science criteria plus separately reported integration (Page 3).

Specimen-bench ID

Classify igneous rocks with a hand lens by texture and composition.

Oral check

The student defends the cooling story the crystals record (Page 4).

Lab notebook

Texture, composition, and each rock’s volcanic origin kept distinct.

How to read a Bright Minds rubric

You are making a decision, not adding up points. For each criterion, decide whether the work is Developing, Proficient, or Mastery — the column language tells you which. A criterion counts as mastered only when the student can both identify the rock and defend the cooling story the crystals record. Each student has three tokens per term; each token retries one rubric criterion. Approved accommodations, equipment failures, and approved absences are handled separately and do not consume these tokens.

▲ Page 2 — Key terms
Igneous Rocks · Vocabulary
Key Terms — What Counts as Correct
Vocabulary
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Accept listed synonyms; use the distinction column to resolve near-matches.

Canonical answerAccepted synonymsCommon confusion / discriminator
Melt & cooling
Magmamolten rock below groundLava is the same melt once it reaches the surface
Intrusive (plutonic)cooled below groundSlow, deep cooling → coarse crystals (e.g. granite)
Extrusive (volcanic)cooled at the surfaceFast cooling → fine-grained or glassy texture (e.g. basalt)
Texture & composition
Texturecrystal size / grain sizeRecords the cooling rate — not how old the rock is
Vesicularfull of gas holesTrapped gas bubbles; pumice can float
Felsichigh-silica, light-coloredSticky, gas-rich melt → explosive; e.g. granite, rhyolite
Maficlow-silica, dark, iron-richRunny melt → gentle flows; e.g. basalt
Bowen’s reaction seriesmineral crystallization orderOrders minerals by the temperature at which they crystallize
Volcano form
Shield volcanobroad, gently sloped coneBuilt by runny mafic lava; gentle eruptions
Composite volcanostratovolcanoLayered ash and lava; explosive, felsic melt
Cinder conescoria coneSmall, steep cone of erupted fragments
▲ Page 3 — Mastery rubric
Igneous Rocks · Mastery Rubric
Six Criteria — Developing / Proficient / Mastery
Rubric
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CriterionDevelopingProficientMastery
Magma, lava & cooling rateConfuses settings or temperature change with elapsed time.Names a trend but cannot calculate or qualify a rate.Distinguishes magma/lava and common settings; calculates assigned interval cooling rates and states their limits.
Texture & crystal sizeCannot describe diagnostic textures.Connects texture to cooling but assumes a unique quantitative history.Describes coarse, fine, glassy, and vesicular textures, using composition and conditions to qualify the inferred history.
Composition & Bowen's reaction seriesCannot order minerals or tell felsic from mafic.Sorts felsic and mafic by color but ignores mineral content.Uses Bowen's reaction series to rank a melt from ultramafic through mafic and intermediate to felsic.
Rock identification (granite, basalt, obsidian, pumice)Confuses common igneous rocks with one another.Names some rocks but not from texture and composition together.Identifies granite, basalt, obsidian, and pumice from texture and composition and justifies each call.
Volcano type & eruption interpretationTreats all eruptions alike.Infers behavior from composition alone.Relates volcano forms to viscosity, volatiles, temperature, and setting, while distinguishing interpretation from an eruption forecast.
Integration (cross-domain)Makes no supported connection between the source and the science.Uses the source but needs help connecting evidence, writing, or limitations to the science.Independently connects History, Reading, and Writing using a cited source, appropriate evidence, a limitation, and a scientific explanation.
What “Mastery” requires
The student identifies the rock and reads its cooling history from the crystals, then ties composition to eruption style — unprompted.
What does not pass
Naming a rock with no cooling story (“it’s basalt” with no “because it cooled fast at the surface”) is Proficient, not Mastery.
Grading it at home

The split between Proficient and Mastery is crystals tell the story: not just naming a rock, but using its texture to say how fast the melt cooled and its composition to predict the eruption. Ask “so what do the crystals tell you?”

▲ Page 4 — Anchor exemplars
Igneous Rocks · Calibration
Anchor Exemplars — To Calibrate Your Ear
Anchors
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Read these before you grade. They show what Mastery and Developing actually sound like, plus the edge cases where you should coach rather than decide on the spot.

Cooling history from texture

▶ Mastery
“The supplied texture and composition support a mafic volcanic interpretation. They do not give one exact cooling rate or eruption history. Volatiles, temperature, and setting also affect behavior; this is not an eruption forecast.”
▶ Developing
“It’s some kind of black rock. Volcanoes just explode. I think the big crystals mean it’s older.”

Integration — Hutton & deep time

▶ Mastery
“Coarse granite crystals mean the magma cooled slowly, deep underground — that takes enormous time. Hutton saw molten rock as part of Earth’s endless engine, forcing granite up through older beds.”
▶ Developing
“Granite is a rock.” (A fact, with no link to cooling time or deep time.)

Edge cases — coach, don’t fail

▶ Crystal size as age
Says big crystals mean an old rock. Coach: crystal size records the cooling rate, not age — slow, deep cooling grows large crystals. Common, fixable.
▶ Color-only composition
Sorts felsic from mafic by color alone. Coach: color hints at composition, but confirm with the minerals present before ranking the melt.
▲ Page 5 — Score sheet (clipboard)
Igneous Rocks · Score Sheet
Unit Score Sheet — One per student
Score Sheet
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Student: ______________________________________    Date: _______________    Guide: _________________________

Mastery criteria — circle one per row

#CriterionDecisionNotes
1Magma, lava & cooling rateDev / Prof / Mast
2Texture & crystal sizeDev / Prof / Mast
3Composition & Bowen's reaction seriesDev / Prof / Mast
4Rock identification (granite, basalt, obsidian, pumice)Dev / Prof / Mast
5Volcano type & eruption interpretationDev / Prof / Mast
6Integration (cross-domain)Dev / Prof / Mast

Specimen-bench ID — technique check

Used a token this session?

☐ No    ☐ Yes — for criterion: __________
Tokens left this term after this session (choose one): ☐ 3   ☐ 2   ☐ 1   ☐ None left

Dev = Developing · Prof = Proficient · Mast = Mastery · Unsure between two levels? Circle the lower one and note what a re-do would need.