Knorringite Garnet: Gemstone Information 

Name Knorringite approved by the CNMMN of the IMA (1968). Named after Oleg von Knorring, Professor of Mineralogy, Leeds University, Leeds, England.
Knorringite is exceptionally rare and is only known from kimberlite pipes. Kao kimberlite, Lesotho; as an inclusion in a type IIa diamond from a kimberlite in the Mirny area, Yakutia, Russia.
Knorringite is Not reported as gem material. which is found as tiny blue-green to lilac grains, forms a series with pyrope. There also exists a knorringite–uvarovite solid solution series. The original material comprising Kn34Py30Uv19Al13An4, or alternatively as 52.7% knorringite if none of the chromium is cast as uvarovite; and the highest knorringite component so far observed is in an inclusion in diamond (66.4 mol.%). The importance of knorringite is
largely as a component in chromium rich pyrope where it affects the colour and physical properties.
Hardness: 7
Refractive Index: 1.790–1.803 (1.875 for calc. end-member)
Specific Gravity: 3.86 (3.835 calc. end-member)