Nifontovite

This excellent crystallised miniature is a fine example of the extremely rare borate, Nifontovite, from Charcas in San Luis Potosí, Mexico.  This polymetallic skarn deposit is defined by an extensive calcium-boron metasomatic envelope and contains over twenty quite varied mineral species.  The Nifontovite crystals measure up to 2.7 cm long and are colourless with a brilliant glassy lustre.  The crystals form a compact group giving an overall slightly milky appearance.  Most crystals are sharply terminated and protrude from a micro-vuggy, cream coloured Calcite matrix.  The back face of the matrix is pervaded with a spray of embedded Nifontovite crystals which make a fine addition to this rare specimen.