Mineral identification chart

By The Gleamite desk, Identification research · updated 2026-08-18

This chart identifies minerals in the order the tests are cheapest: luster sorts metallic from glassy from earthy at a glance, hardness brackets the candidate against a fingernail, coin and knife, and streak — the powder color on unglazed tile — settles the metallics. Twenty minerals cover the overwhelming majority of real finds.

How to work the chart

Sort by luster first: metallic candidates go to the first table, everything glassy, waxy or earthy to the second. Bracket hardness second, with the household kit — fingernail near 2.5, copper coin near 3.5, steel knife or nail near 5.5, glass bottle at the same mark. Streak comes third and mostly for the metallics, where it does its best work; the method and full color list live on the streak test page. Color testifies last, because it lies first.

One scope note: this chart handles single minerals. A speckled or layered stone is a rock — a mixture of mineral grains — and identifies by family on the rock identification chart instead.

Metallic luster

Mineral	Color	Mohs	Streak	The tell
Pyrite	Brass yellow	6–6.5	Greenish black	Striated cubes; knife cannot cut
Chalcopyrite	Deep brass, iridescent tarnish	3.5–4	Greenish black	Knife cuts it
Galena	Bright lead gray	2.5	Lead gray	Extreme weight, cubic cleavage
Magnetite	Iron black	5.5–6.5	Black	Strong magnet response
Hematite	Steel gray to red-brown	5–6	Red brown	Streak wins regardless of surface
Graphite	Dull dark gray	1–2	Gray black	Writes on paper, greasy feel

Glassy, waxy and earthy luster

Mineral	Color habit	Mohs	The deciding check
Quartz	Any — clear to black	7	Scratches glass; no cleavage flash
Feldspar	White, pink, tan	6–6.5	Cleavage faces flash in light
Muscovite mica	Silvery, transparent sheets	2–2.5	Peels into flexible leaves
Biotite mica	Black-brown sheets	2.5–3	Same peel, dark
Calcite	Clear to honey	3	Fizzes in vinegar; splits to rhombs
Dolomite	Pearly white-pink	3.5–4	Fizzes only powdered
Gypsum	White, silky	2	Fingernail scratches it
Halite	Clear cubes	2.5	Dissolves; cubic cleavage
Fluorite	Purple, green, banded	4	Knife marks it; often fluoresces
Apatite	Green-blue	5	Knife barely marks it
Garnet	Red-brown crystals	6.5–7.5	Geometric faces, no cleavage
Olivine	Bottle green grains	6.5–7	Sugary grains in dark rock
Talc	White-green, greasy	1	Softest thing on the chart
Sulfur	Canary yellow	1.5–2.5	Color plus crumbling softness

Two rows carry most of the traffic. Quartz is the commonest answer a chart ever returns, with its full portrait — varieties, fakes, the cleavage-flash trick — at how to identify quartz. And pyrite is the commonest metallic question, with the family split at how to identify pyrite.

When the chart hesitates

Three situations defeat any property table. Coated stones lie about luster and color at once — iron staining is the classic, and the filed-corner test from orange rock identification applies before any row is trusted. Massive habits hide the giveaway crystal forms, which is when hardness plus streak carry the whole identification. And genuinely ambiguous survivors — soft, pale, nondescript — are exactly what the rock identifier app triages fastest, by ranking the plausible rows before you test any of them.

Questions people ask

What are the five main properties for identifying minerals?

Luster, hardness, streak, cleavage and color — in roughly that order of reliability. Luster and hardness are testable in seconds; streak is steadier than surface color; cleavage takes practice to read; and color comes last precisely because impurities and staining change it while the other four hold still.

What is the difference between a rock and a mineral?

A mineral is one substance with one recipe — quartz, calcite, pyrite — while a rock is a mixture of mineral grains, the way granite mixes quartz, feldspar and mica. This chart handles single minerals; rocks identify by grain, layering and family instead, on their own chart.

Why is color last in mineral identification?

Because it lies the most. Quartz alone spans clear, purple, pink, yellow, brown and black; iron staining paints whole hillsides orange; and dye recolors tumbled stones commercially. Luster, hardness and streak survive all of that, which is why the chart leads with them and treats color as a supporting witness.

The Gleamite deskWrites every identification chart on this site from named mineralogical properties — Mohs values, streak colors, specific gravity — sourced from USGS and standard references on a stated date, and runs the same hardness, streak and vinegar checks it tells readers to run.

Sources

The Mohs scale runs talc 1, gypsum 2, calcite 3, fluorite 4, apatite 5, orthoclase 6, quartz 7, topaz 8, corundum 9, diamond 10 — with fingernail, coin and knife as the household brackets — Geology.com, Mohs Hardness Scale, 2026
USGS lists luster, hardness, streak, cleavage and color as the working properties for identifying an unknown mineral — U.S. Geological Survey, identification FAQ, 2026
Search metrics for mineral chart queries are unmeasured on this site — Ahrefs quota is exhausted until 2026-09-01; the SERP was walked by hand on 2026-08-18 instead — Gleamite research log, 2026