THE MOHS HARDNESS SCALE

ten reference minerals and five household probes: who scratches whom

Built as a memo rather than a table: the thing worth hanging it up for reads across the room, with the full reference in smaller type below it.

Three sizes in one archive — from a sheet on the fridge to a poster on the wall.

Formats: A4 · A3 · A2
What you get: Print-ready PDFs, one per size, with every letterform converted to outlines — nothing to install, nothing to shift.
Subject: science · school · reference · classroom

Reference minerals, order and household probes follow NPS (US National Park Service, «Mohs Hardness Scale»); the 1812 date and Vickers figures are from geology.com. The test is destructive: scratch a sample you can spare, on a fresh unweathered surface.

THE SCALE ORDERS, IT DOES NOT MEASURE

The Mohs scale is ordinal: it says who scratches whom, not by how much. The single top step hides a nearly fivefold jump — by Vickers hardness corundum (9) measures 2,035 kg/mm², diamond (10) measures 10,000.

So a 9 out of 10 in mineralogy is nowhere near “almost diamond”: the gap above it is wider than the whole rest of the scale combined.

On the sheet

Reference minerals, order and household probes follow NPS (US National Park Service, «Mohs Hardness Scale»); the 1812 date and Vickers figures are from geology.com. The test is destructive: scratch a sample you can spare, on a fresh unweathered surface.
Colour carries meaning, but meaning never rests on colour alone — the sheet reads in black and white.
Nothing about how it was made: the sheet carries only what the reader needs.

Printing

Three sizes in the archive: A4 — 210×297 mm, A3 — 297×420 mm, A2 — 420×594 mm.
All text is converted to outlines. No fonts to install, and nothing shifts on another machine.
White background and sparing fills — it prints on a home printer without draining the cartridge.
Margins of at least 10 mm: a home printer cannot print to the edge.
No stroke thinner than 0.3 mm, so nothing disappears in print.

Why the numbers can be trusted. Every countable number here is computed from data rather than typed in, and the sheet must pass 7 independent checks before it is allowed to build — how many items there are, the order they come in, and the claim in the highlighted box itself. If one fails, there is no file.

THE MOHS HARDNESS SCALE

THE SCALE ORDERS, IT DOES NOT MEASURE

On the sheet

Printing

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