Named after the Danish geologist Kornerup, who discovered it. One of the rarer gemstones. Not often seen and sometimes quite pricey. Many times included to some degree. This is all I have. I am looking for more.

Colors: colorless, pink, greenish yellow, blue green, sea green, dark green, brown and black.
Refractive Index: ~1.67 - 1.68
Hardness: 6-7
Density: 3.28-3.35
Occurence: Greenland, Sri Lanka, Burma, Kenya, Tanzania, Canada and Madagascar. Star Kornerupines have been found in Burma, but are very rare.

   Named after Benjamin Silliman, minerologist, Yale University. Fibrolite is an allusion to the fibrous nature of this variety. Faceted gems are usually small (under 5.0 carats) and quite rare. Fibrolite from Burma and Sri Lanka are highly prized because of their scarcity. Chatoyant material sometimes yields catseyes, which are also very rare. Material from Kenya rivals Burmese, but tends to be smaller.

Colors: Colorless, greyish, brownish, greenish, bluish and violet-blue. The material I have here is primarily colorless, but under certain light, shows a slight bluish tint.
Refractive Index: 1.65 - 1.68
Hardness: 6.5 - 7.5 Brittle
Density: 3.23 - 3.27
Occurence: Fibrolite occurs in many areas, but only gem sources are listed here. Burma, Sri Lanka, Kenya. Some may be coming out of Brazil.

Please note: These pics seem to show color in the gems, but they are actually colorless. Also know that I found these Sillimanites at an astounding bargain price. I am passing that deal on here. All are well cut.

   From an old Sanskrit word for Ceylon (Sri Lanka), Sinhala. Originally thought to be Peridot, but in 1956 was determined as a new mineral. When cut it is bright and attractive, resembling Citrine, Peridot and Zircon. Somewhat rare as a gemstone. Strangely, large Sinhalites (Sri Lanka) are more readily available than smaller ones.

Colors: Yellow, yellow-brown, dark brown, greenish brown, light pink and brownish pink.
Refractive Index: 1.66 - 1.71
Hardness: 6.5 - 7.0
Density: 3.47 - 3.50
Occurence:  A contact metamorphic mineral in limestones at granite contacts; Alluvial. found in Warren County, New York (no gem value), Northeast Tanzania, and Sri Lanka (major source).

   From the Greek words idos and krasis, meaning mixed appearance, because Idocrase crystal forms resemble those of other species. Vesuvianite from Mount Vesuvius, where the mineral occurs in small, perfect crystals. Idocrase is one of the lesser known and more beautiful collector gems. When properly cut it is as bright and attractive as the grossular Garnets it strongly resembles.

Colors: Colorless, green, brown, white, yellow, red, blue, blue-green, pink and violet.
Refractive Index:  1.70 - 1.72
Hardness: 6 - 7
Density: Not Available
Occurence: Serpentines and related rocks. Contact metamorphic deposits. Alkalic rocks. Regionally metamorphosed rocks. You really wanted to know that, right? Cuttable materials known from Italy, Quebec, New York, Pakistan and Kenya.