Oil paints are made from pigments ground with a binder. Pigments can be organic or inorganic; they can also be natural orsynthetic.
Orangic pigments are carbon based, and they were originally extracted from plant or animal matter. Organic pigments are usually transparent. Inorganic pigments are derived mostly from metals. They tend to be opaque, with low value, low chroma and high opacity and they are chemically stable. Most pigments today are synthetic. Synthetic pigments mimic the effects of natural pigments, and can be organic or inorganic.