Using Gemstone Essences and Elixers
You really need to understand the chemical make-up of what you're mixing up or it can be fatal, deadly fatal.
That said, properly made elixers may be taken internally and essences may be applied externally.
Essence or Elixer, and what is the difference?
An Essence would be applied to the skin to be absorbed and treat specific problem areas and an Elixer is taken by the drop internally and travels through your entire body.
Gemstone essences or elixers are able to bring about the same effects and changes to the body, mind and spirit as the actual gem. The advantage, and somes disadvantage, to them lies in the application.
Many times when a gem is laid on the body it may only have a limited or localized effect. A gem elixer that is taken is sent to your entire body. There are times that it is more practical to use an essence or elixer than to try and carry around a five pound gem. It is usually more practical for your wallet as well.
There is an advantage to wearing or laying on of crystals though when you are experimenting. In particular, they can be quickly removed and its effect will fade much quicker. If there is a specific area you are targeting, laying on the gem would be preferred. In most cases, a gem and an essence can compliment each other nicely when used together.
You need to use caution with anything you ingest, read about gemstone and metal warnings. Never, ever, EVER use Malachite (green stones), Lapis (dark blue stones), or any with sulphur/acid bases to take internally. You can be dead before you hit the floor!
When taken internally, elixers you have made with water can be taken in mouthfuls, those made with an alcohol base are taken in drops. It would be impossible for me to calculate or give directions for doses since sensitive natures may only need a drop or two, and those who are more robust or hardy in their makeup may be fine with five to ten drops.
Essences (and gems themselves) can also be added to your bath water. Be sure to not have the water too warm as the effect can disperse much more quickly. Rose Quartz and Amethyst provide a wonderful and relaxing soak :D