I use the ankh, carved onto an onyx gemstone.
Ankh: It is by Egyptologists called the symbol of life. It is also called the "handled cross", or crux ansata. It represents the male triad and the female unit, under a decent form. There are few symbols more commonly met with in Egyptian art. In some sculptures, where the sun's rays are represented as terminating in hands, the offerings which these bring are many a crux ansata, emblematic of the truth that a fruitful union is a gift from the deity.
Onyx: Black Onyx is a popular and powerful gemstone. The keywords behind Black Onyx meaning are Intuition, Rejuvenation, Divination, Strength, Change, Balance, Grounding, Focus, Self Confidence, Banishing Negativity, Protection, Letting Go, Decreased Sexual Desires