In this context, oil refers to the fats (lipids) manufactured by plants and animals. Most are liquid at room temperature, but some are not (these are often referred to as “fat” or “butter” or “tallow”). Oils are very energy rich, as that is generally their purpose in life, to store energy. Oils as a raw material have a variety of uses, from food to fuel to lubricants to cosmetics and others (sometimes all of the above), depending on their specific properties. Fat-rich seeds are the most common source of oil, but there are several others. Petroleum is “fossilized” oil, or plant and animal oils that have been subjected to temperature and pressure over millions of years.
Seed oil. This oil is usually obtained by pressing the seeds to expel the oil, either with or without heating the seed. As a side note, the material remaining after expelling is often used for another purpose, such as fuel or fodder. There are many very important seed oils. Some examples include:
Argan oil (Argan tree, Argania spinosa)
Beech oil (Beech tree, Fagus spp.)
Canola oil, colza oil (Rape, Brassica napus). Note: other members of the cabbage family (Brassicaceae) are also seed-oil producers, such as: abyssinian cabbage, crambe, mustard, and radish.
Animal oil. Animal-based oils are not used nearly to the extent that they once were — and some are now illegal. However, it’s worth mentioning for the sake of history that some animal oils were once incredibly important. For example: whale oil and tallow candles at one time lit the world. Musk oil from the male musk deer was used in perfumery and was one of the most valuable substances in the world. Today, lard and butter are important foods, and fish oils rich in omega-3 fatty acids are popular dietary supplements. Neatsfoot oil (rendered from the shin and foot bones of cattle) is still a common treatment for leather.
Mineral oils. All “mineral” oils have organic origins. Amber oil, made by heating amber (fossilized resin) is used in perfumery. Petroleum, of course, is the single most important modern source of fuel oils and lubricants. Coal yields cresol, which has many industrial uses, such as in the preparation of dyes and disinfectants.
From the Crazy Useful Catalog:
Crazy Useful Things
A Dictionary of Natural Resources and Their Products