In New York, the grass is finally a lush green and the trees are fully clothed in leaves, so maybe it's appropriate that May's birthstone is emerald; such a descriptive, iconic shade of...green.
I have a couple little faceted emeralds that my father bought for me in Cartagena, Columbia. I have yet to make them into jewelry, but I'm excited to design something for myself.
Emerald
Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium and sometimes vanadium. It's pretty hard (7.5-8), but tends to be highly included, so the toughness isn't great. According to the Gemological Institute of America (GIA), three-phase inclusions in Colombian emeralds contain tiny crystals of rock salt, liquid, and a bubble of gas - meaning there can be all sorts of stuff trapped in those little gems.
Use and Meanings
Getting back to green - I think because green is the color associated with the heart chakra, many of the green color stones relate to love, emotions, and matters of the heart. Emerald is said to help open the heart, promote healing of the physical and emotional heart, and increase prosperity. Another beautiful green stone is prehnite. It's a lovely shade of pale green. Prehnite is said to be a stone of unconditional love, so a necklace is a perfect way to wear it close to your heart.