The distinctive red coloured crystals in ruby zoisite are the mineral corundum, red corundum is better known as ruby. Only red corundum is entitled to be called ruby whilst all other colours including blue and yellow are known as sapphire. Ruby zoisite or ruby in zoisite as it's also sometimes known is used primarily as a lapidary material because of its striking colour but it can be a difficult stone to work with because of the difference in hardness of the two minerals. Zoisite grades 6½ on Mohs scale of mineral hardness whilst corundum which is significantly harder, grades 9.
In the world of crystal healing ruby zoisite is said to enhance psychic powers including the ability to enter a trance. It can to help increase creativity and uniqueness without losing connection with humanity and provides amplification of the entire energy field of the body.
Ruby zoisite from Africa is generally known as anyolite which comes from the Maasai word anyoli meaning 'green') but in Tanzania the Maasai prefer to call it ruby in zoisite as an expression of pride that precious ruby can be found on their land.
Ruby zoisite is often confused with ruby in fuchsite which has a very similar appearance but the latter is more common hence considerably cheaper and the vast majority of stones come from India.