Bergamot (Citrus bergamia)
It's convenient how the Latin names for most citrus notes start Citrus. Think of them as a good place to start learning binomial nomenclature.
Bergamot is a very common perfumery ingredient, and it's a note in an absurd number of both male and female fragrances. That's because it goes with just about everything. Not sure what to put at the top? Bergamot to the rescue!
You might be familiar with the odor from Earl Grey tea. You won't find bergamot at the store to eat, but the essence of the peel is used as a flavor. The scent won't overpower your blends, and will add a nice citrus note. I find it has a light floral aspect to it. Arctander describes its top notes as sweet and fresh, with an oily-herbaceous and slightly balsamic body. This is an exciting oil, and it won't cost you hundreds of dollars.
Like many citrus oils, the essential oil is produced via cold pressing of the peel. I have found a steam-distilled bergamot at Stillpoint Aromatics, but I haven't tried it myself. I'm mostly curious as to whether the steam distillation removes the photo-sensitizing elements of bergamot oil, like it does for lemon and lime. While I said in the first post that I wouldn't write about safety, bergamot oil is strong photo-sensitizer, and should be used with caution in leave on products. If you would like to use it in a leave on product, either dilute heavily or look into bergaptene free or FCF (furanocoumarin free) oils.
Fresh bergamot oil should be green or greenish-yellow. Bergamot doesn't get better with age, so unless you know you need a lot, start with small bottles so you know that you have a fresh oil.
Other oils with a bergamot note:
Bergamot Mint (Mentha citrata)
Bee Balm/Monarda/Wild Bergamot (Monarda Fistulosa)