Named after American geologist Benjamin Silliman, this beautiful gemstone is both beautiful and rare. Sillimanite has been a relatively unknown gem until the 1990’s where a significant deposit was discovered in Orissa, India. Sillimanite is not only scarce but at times even difficult to identify, and only skilled lapidaries are able to cut this stone to portray all its brilliance. Sillimanite can be found in white, blue, yellow, brown and green and has a beautiful silky lustre to it.