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Mineral
Pigments
There
are five main minerals used as pigments, they are azurite and
malachite (copper minerals of blue and green), orpiment (brilliant
yellow), cinnabar (bright red), and lapis lazuli (clear blue).
Other colors can also be made using simple chemistry.
Copper is an
important element in making pigments. It produces the colors
that the earth pigments cannot.
Verdigris - This
was an early artificial lime-blue pigment made by sandwiching
layers of copper and grapeskin crushings, apple cider, or acetic
acid together. It is not a very reliable pigment.
Viridian - This
pigment is made from chromium hydroxide and is bright emerald
green in color.
Prussian
Blue
- This is a greenish-blue pigment made from iron salt, potash,
and blood.
Chromes - There
are a variety of chrome pigments ranging from yellow to orange
to green. All of these pigments are slightly toxic.
Manganese dioxide
is the base for several pigments, specifically manganese blue,
manganese violet, and manganese black.
Cadmium is a
slightly toxic pigment that can be found in zinc mines. It has
a wide range of colors in the red-yellow spectrums. The colors
usually seen are cadmium red, red-purple, deep yellow, yellow-lemon,
and yellow-orange.
Lead - Flake
white or lead white is made using the stack method. This consisted
of using clay pots containing vinegar and stacking with horse
manure, tanners bark or grapeskins to provide carbon dioxide
and warmth. This process would corrode lead, forming lead carbonate.
The lead carbonate is then washed, dried, and ground. White lead
dust is poisonous.
Alizarin - This
is a synthetic pigment derived from coal tar. The colors it produces
range from scarlet (Alizarin Crimson) to maroon (Alizarin Madder
Light).
Asphaltum (black)
is made from asphalt.
Cobalt - This
is an element whose name means "goblin of the mines."
Cobalt is blue and is used in the manufacture of blue glass and
ceramic pigments. Cobalt violet can be made from the combination
of cobalt and arsenic (highly toxic) or cobalt phosphate (non-toxic).
Zinc
White
- This non-toxic, semiopaque pigment is made by burning zinc
vapors. It is cold white.
Cerulean
Blue
- This pigment is made from heating cobalt sulfate with tin salts
and silica. It is slightly cooler than Cobalt Blue having a greenish
tinge. |