March 25, 2009
Theme Thursday - Mineral
Make Sure You Get Enough Vitamins and Cadmium Yellow
Vincent Van Gogh apparently ate paint straight from the tube and so did Emily Carr’s monkey Woo. Maybe they were just looking to supplement their mineral intake.
Many pigments found in today’s oil or acrylic paints are synthetic or vegetable based but many are still based on minerals mined from the earth.
The making of paint was one of the earliest technologies humans developed. By using different coloured earth, or grinding soft rocks to a powder, multi-coloured images could be made. The colours found in prehistoric cave paintings come from Red and Yellow Ochre; types of iron oxide. In Tutankhamen’s tomb, alongside the artifacts, a small paintbox was found containing powdered Gypsum, Orpiment, Hematite and Malachite.
The colour of paint is derived from the small coloured particles suspended in a carrier oil or a binder.
White pigments were made from lead which is now replaced by the less toxic zinc and titanium. The mineral Cerussite was used to make lead paints that Queen Elizabeth I wore as a cosmetic.
Cadmium yellow is made from Cadmium Sulphide. The name Cadmium originates from the Greek kadmeia, meaning Cadmean earth which was first found near Phoenician Prince Cadmus’s city of Thebes.
Many of the blues and greens we see today are derived from copper. Malachite is a green pigment used from antiquity until the 1800s. It is essentially copper carbonate.
The name "Cobalt blue" comes from the German Kobold; a goblin that haunts underground places such as mines. Cobalt was thought pollute other mined elements such as silver. The pigment Cobalt Blue is an oxide of cobalt made by roasting cobalt ore.
The rare gem Lapis Lazuli has always been highly prized for its vivid blue. Lapis Lazuli is ground to make an ultramarine pigment for oil paints. Medieval artists used it for the blue in Virgin Mary's cloak.
Vermilion is a sulphide of mercury found naturally as Cinnabar. Cinnabar pigment is used in Chinese carved laquerware.
Beautiful Manganese Blue was a favourite of fresco painters. However, it was found to be highly toxic and ingestion or inhalation could cause a nervous system disorder. It is no longer sold.
Another class of pigment consists of the earth tones, such as sienna or umber. Umber is a natural brown clay of iron and manganese oxides. When heated it becomes burnt umber
Magenta was originally called fuchsine and in 1859 it was first made from coal tar dyes. The name of the colour was soon changed to magenta, after the Battle of Magenta fought at Magenta, Lombardy-Venetia.
I think it all looks good enough to eat!