NIFONTOVITE: Charcas, Charcas Municipality, San Luis PotosÃ, Mexico. Dimensions: 2.0 x 0.45 x 0.45cm, thumbnail, 0.56g. Nifontovite is a very rare hydroxylated calcium borate hydrate with the best-of-species coming from Charcas! This is a stunning, perfect, colorless, transparent gem crystal with a sharp termination and it exhibits an absolutely glassy luster. It is in excellent condition. These are some of the largest for the species! Buyer pays USPS Priority Mail shipping. Thank you for reviewing this listing and see my other items!