⚛️ Minerals — printable rubric packet (Geology Unit 01). 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
Minerals — 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 01 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).

Mineral-ID lab

Streak, hardness, cleavage, luster, and the acid test on a specimen set.

Oral check

The student reasons from the physical properties aloud (Page 4 anchors).

Lab notebook

Contemporaneous record of streak, hardness, cleavage, and the unknown ID.

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 run the test and justify why that property separates one mineral from another. 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
Minerals · 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
Defining a mineral
Mineralnaturally occurring inorganic solidOrdered internal structure and characteristic composition; distinguish the material from a whole rock
Crystallineordered internal structureAtoms in a repeating lattice; this is what gives crystal faces
Rockaggregate of mineralsMade of one or more minerals; a rock is not itself a mineral
Physical-property tests
Streakpowder color on a plateRead on porcelain; can differ from the surface color
Lustermetallic / non-metallic shineHow the surface reflects light — independent of color
Mohs hardnessordinal scratch-resistance scaleBracket with approved evidence; 8 is not twice as hard as 4
Cleavageflat breakage planesCount the directions; smooth planes, not rough breaks
Fractureirregular breakConchoidal (curved) in quartz; no flat planes
Identification & special tests
Carbonate-test evidencesupplied or approved reaction recordOne observation to combine with other properties; not a required home acid procedure
Crystal habitcharacteristic growth shapeCubic halite, six-sided quartz — the shape when free to grow
Dichotomous keybranching ID keyEach step is a yes/no choice; work it end-to-end to a name
Grade / recoveryconcentration / recovered fractionApply grade to feed and recovery to contained metal; they are not the same percentage
Resource / reservegeological occurrence / evaluated recoverabilityA classroom mass balance does not establish economic or engineering feasibility
▲ Page 3 — Mastery rubric
Minerals · Mastery Rubric
Six Criteria — Developing / Proficient / Mastery
Rubric
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CriterionDevelopingProficientMastery
Mineral identity & resource quantitiesConfuses a mineral, rock, grade, and recovered material.Names properties or percentages but misuses their meaning.Explains mineral identity and rock composition; applies assigned density, grade, and recovery calculations without equating a resource with a reserve.
Streak & lusterReads the specimen’s surface color as its streak; cannot name luster.Gets a streak on the plate but forgets that streak can differ from surface color; luster call is inconsistent.Powders the mineral on the porcelain plate to read true streak, and classifies luster as metallic or non-metallic to narrow the field — e.g. pyrite’s greenish-black streak under a brassy metallic shine.
Mohs hardnessGuesses hardness by appearance; misuses the kit.Runs scratch tests but reverses which scratches which, or reports a single number instead of a range.Uses fingernail, copper penny, glass plate, and steel nail methodically to bracket hardness on the Mohs scale and reads it accurately (e.g. calcite ~3, quartz 7).
Cleavage vs. fractureUses the terms interchangeably or not at all.Defines both but misreads a specimen — calls conchoidal fracture “cleavage” or misses a plane.Distinguishes flat cleavage planes from irregular fracture, counts cleavage directions, and cites mica’s one perfect cleavage against quartz’s fracture.
Property evidence & the dichotomous keyGuesses without a reference or ignores the approved procedure.Uses a property but overlooks uncertainty or another possible identity.Combines approved or supplied property evidence with a key, explaining uncertainty and why one result alone need not establish identity.
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 both runs the physical-property test and justifies why that property separates one mineral from another, in their own words, without prompting.
What does not pass
A name with no test (“it’s gold, so pyrite”) is Proficient, not Mastery. Reading a property off the specimen with no reasoning is Proficient.
▲ Page 4 — Anchor exemplars
Minerals · 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.

Grading it at home

Work down the criteria one at a time. Ask the student to reason from the property rather than recall — “why can’t this be quartz?” Hardness, streak, and cleavage are what separate look-alikes. Running the test is Proficient; explaining why the property rules a mineral in or out is Mastery.

Streak, hardness & the acid test

▶ Mastery
“It fizzed under the dilute acid, so it’s a carbonate — and the steel nail scratched it easily, hardness near 3, with a white streak and rhombic cleavage. That’s calcite. Hardness rules out quartz: quartz would scratch the glass, calcite won’t.”
▶ Developing
“It’s kind of gold, so… pyrite? And it looks hard, I think — I didn’t really do the streak, the outside was already that color.”

Integration — Hutton & deep time

▶ Mastery
“These crystals are the slow record of Earth’s making — Hutton read deep time in rock like this. A mineral’s ordered lattice took time and the right conditions to grow, one atom at a time.”
▶ Developing
“Hutton was a geologist.” (A name, with no link to the crystals or deep time.)

Edge cases — coach, don’t fail

▶ Right name, no test
“It’s calcite.” Correct, but stops there. Coach: “how do you know it’s not quartz?” If they reach the acid fizz and soft hardness → Mastery; if not → Proficient.
▶ Streak skipped
Reads the surface color as the streak. Coach the porcelain plate; not yet on the streak criterion until they powder the mineral to read the true color.
▲ Page 5 — Score sheet (clipboard)
Minerals · Score Sheet
Unit Score Sheet — One per student
Score Sheet
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Student: ______________________________________    Date: _______________    Guide: _________________________

Mastery criteria — circle one per row

#CriterionDecisionNotes
1Mineral identity & resource quantitiesDev / Prof / Mast
2Streak & lusterDev / Prof / Mast
3Mohs hardnessDev / Prof / Mast
4Cleavage vs. fractureDev / Prof / Mast
5Property evidence & the dichotomous keyDev / Prof / Mast
6Integration (cross-domain)Dev / Prof / Mast

Mineral-ID lab — 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.