374 Carat Lithium Niobate
World’s Largest Faceted Lithium Niobate Gemstone
Lithium Niobate is used in optics and electronics and was an early diamond simulant because of its high refractive index, 2.3. It was quickly replaced by other simulants because of its relative softness, 5.5 Mohs. It is still cut by custom faceters for collectors and some jewelry due to its incredible dispersion. Here is an amazing example faceted in a gargantuan 374 carats and measuring 38 mm diameter by Hashnu Stones & Gems.
The international Gem Society has recently featured this amazing gemstone in their article on dispersion.