Essential oils are volatile, oily, water-insoluble, mostly colorless or light colored liquids, with a characteristic strong smell. They do not leave oily stains on paper, and oxidize and resinify when exposed to light and oxygen.
Essential oils are very volatile, in other words, easily evaporated, plant extracts, consisting of hundreds organic compounds – terprenes, alcohols, aldehydes, ketones, and other hydrocarbons, produced by the essential oil plants. These oils have numerous benefits and the smell of those plants they were extracted from. There are about 3,000 plants that can be used to extract essential oils. Essential oils may be contained either in the whole plant or in its certain part, such as stem, root, fruits, blossom clusters, flowers, needles, leaves, wood, and seeds. The percentage of content of the essential oil in a plant compared with its total weight ranges between 0.5% and 6%.
The quality of essential oils is the property defining its efficacy and safety. The quality depends on the extraction method, plant growing area, harvesting period, and storage time. High quality essential oil is transparent and uniform, without residue or inclusions. After a drop of essential oil evaporates from paper, there should be no greasy stain left, even though slight coloration of paper is possible if the oil has color.
Shelf life of essential oils (apart from citrus essential oils) is unlimited if the oil is stored in a dark place in an air-tight packaging at a temperature from 0 to 30˚С. It is known that fine oils, same as fine wines, are becoming more refined as a result of long-term storage (these are frankincense, rose, neroli, and daffodil).
The cost of essential oils is defined, on one hand, by their quality (high quality oils are expensive) and the addition of a diluting agent, on the other hand – by the value and rarity of the essential oil plants, and finally – by the percent content of the essential oil in a plant (for example, 100kg of eucalyptus yield 3kg of essential oil, while 100kg flowers of bitter orange would only yield only 50g of essential oil). A significant increase in cost is stipulated by the deterpenation.
Pure essential oils are the ones that are not diluted with any artificial substances. These are the plant oils in their original form after the distillation that weren’t modified in any way. Many companies sell the so called “scented” oils that contain artificial additives. These are the oils of commercial quality at best; sometimes the quality may be even lower.
Based on their effect over body, essential oils are split into the following categories: cleansing, energizing, toning, relaxing, harmonizing, invigorating, refreshing, stimulating, and tranquilizing.
Cleansing essential oils:
geranium, lavender, lemongrass, sweet orange, tuberose, rosemary, sage, and lemon.
Energizing essential oils:
bergamot, ylang-ylang, geranium, jasmine, cardamom, mandarin, bigarade, rose, and sandalwood.
Toning essential oils:
basil, bay, clove, lemon, melissa, nutmeg, mint, cinnamon, palmarose, rosemary, citronella, thyme, sage, fir, and ginger.
Relaxing essential oils:
valerian, oregano, lavander, frankincense, myrrh, juniper, chamomile, and jasmine.
Harmonizing essential oils:
geranium, jasmine, oregano, marjoram, mimosa, orange, rose, sandalwood, and mandarin.
Invigorating essential oils:
angelica, lavender, melissa, basil, cajeput, nutmeg, mint, rosemary, vervain, cedar wood, lemon, and vetiver.
Refreshing essential oils:
fir, helichrysum, mint, lavender, mandarin, fir, orange, and lemon.
Stimulating essential oils:
helichrysum, cilantro, black pepper, lavender, nutmeg, clove, eucalyptus, mint, rosemary, vervain, juniper, hyssop, and lemon.
Tranquilizing essential oils:
dill, geranium, jasmine, chamomile, melissa, vanilla, and bigarade.