Pigment

A pigment is an insoluble solid that colours by being suspended in something rather than dissolved in it, which is what distinguishes it from a dye. That physical difference decides almost everything about how it behaves: a pigment sits on or in a surface as particles, and its colour, opacity and durability all follow from the particles' size and refractive index as much as from the chemistry.

The history here is largely a history of toxicity being traded away. Lead white, vermilion, Scheele's green and chrome yellow were all superb and all poisonous, and the modern replacements were adopted for that reason rather than for looking better.

• Mineral

  Azurite

  the principal blue of European painting before ultramarine became affordable

• Material

  Charcoal

  as vine and willow charcoal for drawing, and as the black in the oldest paintings there are

• Mineral

  Cinnabar

  as vermilion, ground from the mineral or later made synthetically

• Element

  Cobalt

  cobalt blue, in glass and ceramic glaze since antiquity

• Element

  Erbium

  a pink colourant in glass and glazes, a minor use beside its optical one

• Mineral

  Hematite

  red ochre, in use for at least 40,000 years

• Mineral

  Malachite

  the green of much ancient and medieval painting, before synthetic greens

• Mineral

  Pyrolusite

  a black pigment used since the Palaeolithic

• Mineral

  Rutile

  as synthetic titanium dioxide, the white pigment in most paint and paper

• Mineral

  Stibnite

  ground as kohl, a use documented across the ancient Mediterranean and Near East

• Element

  Strontium

  as the standard red in pyrotechnics

• Mineral

  Talc

  as a white filler and extender rather than a colourant in its own right

Each of these uses is established and cited on its own. Whether something counts as an ore, for instance, depends on grade, price and era — and those qualifications are shown alongside it.