Mohs Hardness Scale Flashcards

Mohs Hardness Scale flashcards — the free 17

Every question and answer on the free cards, written out. Check them against your own textbook before you spend anything.

Mohs 1

Talc — the softest of the ten; every other reference mineral on the scale scratches it

Mohs 2

Gypsum — a fingernail scratches it; talc will not

Mohs 3

Calcite — about a copper coin's hardness; a steel blade scratches it easily

Mohs 4

Fluorite — a steel blade scratches it, and it will not scratch window glass (≈5.5)

Mohs 5

Apatite — sits just below a steel blade and window glass, both about 5.5

Mohs 6

Orthoclase feldspar — the softest of the ten that scratches window glass (≈5.5)

Mohs 7

Quartz — scratches glass and a steel blade, and neither of them scratches quartz

Mohs 8

Topaz — scratches quartz; nothing in an ordinary pocket test kit scratches topaz

Mohs 9

Corundum — of the ten, only diamond scratches it (some synthetics and moissanite also will)

Mohs 10

Diamond — scratches every other mineral, and no natural mineral scratches it

Fingernail

Mohs ≈2.5 (2 to 2.5 in print) — scratches talc and gypsum, but not calcite (3)

Copper coin

Mohs ≈3 — but modern UK 1p/2p and US cents are only copper-plated, over steel or zinc

Steel knife blade

Mohs ≈5–5.5 — feldspar (6) and quartz (7) scratch it; apatite (5) does not

Window glass plate

Mohs ≈5.5 — quartz scratches glass and glass will not scratch quartz; the classic test

Streak plate (unglazed porcelain)

Mohs ≈6–7 — a mineral harder than the plate leaves plate powder, not a streak

Is the Mohs scale linear?

No — it is ordinal. Britannica puts 3→4 at about 25% and 9→10 at over 300%; the ratio depends on the method

Corundum (9) to diamond (10) — how big is one step?

Huge — by indentation (Knoop) hardness diamond is roughly 3–4× corundum, one Mohs step above it

Mohs Hardness Scale flashcards — questions people ask

How many cards are in the Mohs Hardness Scale flashcard deck?

The Mohs Hardness Scale deck on PuzzlePage has 17 cards, and all 17 are free to play and free to download with no account and no payment. 17 cards. The scale has exactly ten reference minerals — that is the whole scale, not a selection. The other seven are the standard field comparators and the one thing about the scale that is most often taught wrong.

What is on the mohs hardness scale flashcards?

The ten reference minerals of the Mohs scale in order, the everyday objects used to bracket a hardness in the field, and why the scale is ordinal rather than linear. Cards look like this: Mohs 1 → Talc — the softest of the ten; every other reference mineral on the scale scratches it; Mohs 2 → Gypsum — a fingernail scratches it; talc will not. The deck is written for grades 6–12 and filed under science.

Can I study mohs hardness scale flashcards online for free?

Yes. All 17 cards of the Mohs Hardness Scale deck play free in any web browser at puzzlepage.app, with no account, no app and no card details. It works on a phone, tablet, Chromebook, laptop or classroom projector. Practice mode flips through the cards with nothing scored; quiz mode makes you answer each card before it flips, times the run and scores it.

Are the mohs hardness scale flashcards accurate?

Every card in the Mohs Hardness Scale deck cites two independent published sources — two different organisations, not a standards body and a site reprinting it — and a script checks that, rather than taking the writer's word for it. A second specialist then re-verified the deck against sources of their own, without reading the citations first. That is the difference from a user-generated flashcard site, where the cards are whatever a stranger typed and nobody is accountable for them.

Can I print the mohs hardness scale flashcards?

Yes. The Mohs Hardness Scale cards are available as a printable double-sided PDF to cut up, as well as playable in the browser. The whole 17-card printable is free to download, with no account.

How should I use the Mohs Hardness Scale deck to revise?

Start in practice mode and go through the Mohs Hardness Scale deck once without scoring, to find out which cards you already know — the deck is dealt in a different order every time you open it, so you are recalling the card rather than its position. Then switch to quiz mode, which times and scores the run and lets you re-run only the cards you missed. Use the "flip deck" control to swap which side is the question: recognising an answer is much easier than producing one, so a deck you find easy one way round is usually the harder and more useful drill the other way. Two or three short sessions across a week beat one long one, which is the whole reason flashcards work.

What grade level are the mohs hardness scale flashcards for?

The Mohs Hardness Scale deck is written for grades 6–12. Because the cards are plain term-and-answer pairs, they are also used outside that band — by adults revising science, and by teachers running them as a whole-class starter on a projector.