• ochre colors and earths

  • French organisation for the promotion of ochres and coloured earths

  • shades of ocher
accueil en ocher production

ochres and coloured earths

Main qualities

  • covering and colouring capacity: can be mixed in all liquids, no reaction with limes, silicates and cements,
  • not altered by ultraviolet rays,
  • non-toxic,
  • relatively low cost.

What are coloured earths used for?

  • paint, colourwash: 80%
  • Colouring concretes: 9%
  • Colouring cardboard, rubber, wax: 8%
  • Colouring snow clearance salt, agricultural use, animal feed: 3%

What were they used for?

  • Food dye: pork sausage skins, chocolate during the  war when there was a shortage of cocoa, snuff, Gitane Maïs cigarette paper, cheese  crusts, and the like.
  • As a medicine: desiccative and astringent properties (ferruginous                 substances), for stomach ache in the Middle Ages.
  • To clean silverware, to polish metals, mirrors, to revive the colour of terra cotta flagstones.
  • To protect wood from water (shutters, hulls of boats and so on).
  • Manufacturing of wallpapers and linoleums.
  • To colour rubber.
  • Cosmetics.
colored earths mill

Extraction

There are two types of sites: in Vaucluse, for example, you can  find open air quarries consisting of an ochreous sand cliff which  contains 10% to 15 % of pure ochre, while in Burgundy the mines are about  thirty metres deep and the ore is rather pure. The seam is limited by a  yellow bed of clay that should not be mistaken for ochre.

the old ocher mines

Separation

First of all the ore must go through the washing process, which is done by malaxation under running water. Sands and the impurities settle in V shape decantation drains, while the fine colouring particles, finer and lighter, move towards mud tanks.

ochre mine

Evaporation and drying

After drainage, the earth (known as washed earth) is left in the basins  to be dried. It is then taken and cut into loaves (or brioches).

ochre loaves

Machining and conditioning

It is fired to obtain various colours (the  red is obtained by calcination of the yellow ochre), then crushed, sifted and  put into bags (barrels in old times).

ensachage-des-ocres-en-afrique-du-sud

Samples

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  1. natural sienna ardennes
  2. natural sienna italy
  3. calcined sienna ardennes
  4. calcined sienna italy
  5. yellow ochre vaucluse
  6. yellow ochre nièvre
  7. icles ochre
  8. havane ocre
  9. dunkel ocre
  10. red ochre vaucluse
  11. red ochre nièvre
  12. hematite nièvre
  13. natural umber Italy cpr
  14. calcined umber Italy aek
  15. calcined umber Italy cccn
  16. natural umber Cyprus hg.or
  17. natural umber Cyprus fl.or
  18. natural umber Cyprus b.c.or
  19. calcined umber Cyprus b.or
  20. yellow earth
  21. red earth Sardinia
  22. Rome black
  23. red Pozzuoli
  24. red ercolano
  25. venitian red