Iolite. A silicate of alumina, iron and magnesia, having a bright blue color and a vitreous or glassy luster. It is remarkable for its dichroism, and is also called dichroite.
“At the least whosoever has the spirit of Christ, shall find that spirit in him striving against that which is contrary, and by little and little gaining ground. Where there is no conflict, there is no spirit of Christ at all.”
–Richard Sibbes, Description of Christ