This packet is everything a parent or guide needs to assess Unit 01 at home — the learning targets, the answers that count as correct, the mastery rubric, calibration examples, and a clipboard score sheet. No multiple-choice test: the student shows mastery by running the mineral-identification lab and reasoning from physical properties aloud.
By the end of the Minerals unit, a student should be able to:
Six criteria, each judged Developing / Proficient / Mastery (Page 3).
Streak, hardness, cleavage, luster, and the acid test on a specimen set.
The student reasons from the physical properties aloud (Page 4 anchors).
Contemporaneous record of streak, hardness, cleavage, and the unknown ID.
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. A student carries three tokens per term; one token buys a re-do of one criterion on another day, so a single bad afternoon never sinks the unit.
Accept any answer in the synonyms column — they are pre-approved as equivalent. The third column flags the confusions that look close but are not yet, so you can coach precisely.
| Canonical answer | Accepted synonyms | Common confusion / discriminator |
|---|---|---|
| Defining a mineral | ||
| Mineral | naturally occurring inorganic solid | Must be crystalline with a definite composition — all four requirements |
| Crystalline | ordered internal structure | Atoms in a repeating lattice; this is what gives crystal faces |
| Rock | aggregate of minerals | Made of one or more minerals; a rock is not itself a mineral |
| Physical-property tests | ||
| Streak | powder color on a plate | Read on porcelain; can differ from the surface color |
| Luster | metallic / non-metallic shine | How the surface reflects light — independent of color |
| Mohs hardness | scratch scale 1–10 | A range you bracket with the kit, not a single guessed number |
| Cleavage | flat breakage planes | Count the directions; smooth planes, not rough breaks |
| Fracture | irregular break | Conchoidal (curved) in quartz; no flat planes |
| Identification & special tests | ||
| Dilute-acid fizz test | carbonate test | A drop of dilute acid fizzes on calcite — confirms a carbonate |
| Crystal habit | characteristic growth shape | Cubic halite, six-sided quartz — the shape when free to grow |
| Dichotomous key | branching ID key | Each step is a yes/no choice; work it end-to-end to a name |
| Criterion | Developing | Proficient | Mastery |
|---|---|---|---|
| What a mineral is | Calls any solid a mineral; says a rock is a mineral. | Recites part of the definition but misses a requirement (e.g. forgets “inorganic” or “crystalline”). | States all four requirements — naturally occurring, inorganic, crystalline, definite composition — and explains a rock is made of minerals. |
| Streak & luster | Reads the surface color as streak; cannot name luster. | Gets a streak on the plate but forgets it can differ from surface color; luster call is inconsistent. | Powders the mineral on the porcelain plate to read true streak and classifies luster metallic or non-metallic to narrow the field. |
| Mohs hardness | Guesses 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, penny, glass plate, and steel nail to bracket hardness on the Mohs scale and reads it accurately (calcite ~3, quartz 7). |
| Cleavage vs. fracture | Uses 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 directions, and cites mica’s cleavage against quartz’s fracture. |
| Special tests & the dichotomous key | Skips the acid test; cannot follow a key past the first branch. | Runs the dilute-acid fizz test but forgets what it confirms, or loses the thread in the key. | Applies the dilute-acid carbonate fizz test, folds in density and crystal habit, and works a key end-to-end to name an unknown. |
| Integration (cross-domain) | Treats the science as isolated facts. | Names a link to history, reading, or writing but cannot defend it. | Connects the unit across History · Reading · Writing and defends why it matters. |
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.
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.
Student: ______________________________________ Date: _______________ Guide: _________________________
| # | Criterion | Decision | Notes |
|---|---|---|---|
| 1 | What a mineral is | Dev / Prof / Mast | |
| 2 | Streak & luster | Dev / Prof / Mast | |
| 3 | Mohs hardness | Dev / Prof / Mast | |
| 4 | Cleavage vs. fracture | Dev / Prof / Mast | |
| 5 | Special tests & the dichotomous key | Dev / Prof / Mast | |
| 6 | Integration (cross-domain) | Dev / Prof / Mast |
☐ No ☐ Yes — for criterion: __________ Tokens remaining: ☐ 3 ☐ 2 ☐ 1 ☐ 0
Dev = Developing · Prof = Proficient · Mast = Mastery · Unsure between two levels? Circle the lower one and note what a re-do would need.