Horsetail (Equisetum arvense) extract is something I use regularly. Horsetail is a plant with a hollow stem and feathery branches, and can resemble a horse’s tail.
In the past, horsetail has also been used to polish pewter and lightly sand wood. The reason for this is that silica crystals form on the stem and feathery branches of the plant as it dries. This gives the plant and light abrasive feel.
It is this same silica that makes horsetail such a valuable herb for medicinal and cosmetic purposes.
Studies are ongoing about all of the various benefits of silica. Silica helps with the formation of bone and collagen. It helps strengthen hair and provides volume. I add it to my clay mix that I use daily to clean my hair. I have the added benefit of having a friend north of the city who has lots of horsetail growing on her property. She always has some to spare so I get to make my own extract!