serendibite

{{Infobox mineral | name = Serendibite | image = File:Serendibite-452545.jpg | alt = | caption = A relatively sharp, vitreous black crystal of serendibite from Le Oo, in Mogok Township, measures: 16 x 13 x 8 mm | category = Inosilicates | formula = (Ca,Na)2(Mg,Fe2+)3(Al,Fe3+)3[O2|(Si,Al,B)6O18] | IMAsymbol = Ser | strunz = 9.DH.40 | dana = 69.2.1a.6 | system = Triclinic | class = Pinacoidal () (same H-M symbol) | symmetry = P | unit cell = | color = pale yellow, blue-green, greyish blue, black | habit = | twinning = Polysynthetic on {0–11} is common | cleavage = None observed | fracture = Uncommon, conchoidal | tenacity = | mohs = 6.5 – 7 | luster = Vitreous | streak = White | diaphaneity = Transparent, Translucent,Opaque | gravity = 3.42 – 3.52 (measured) 3.47 (calculated) | polish = | opticalprop = Biaxial (+) | refractive = 1.701 – 1.706 | birefringence = | pleochroism = Visible,strong, color: green, blue, yellow, light blue, bluegreen, light yellow | 2V = Measured: 80° | dispersion = strong | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references = }} Serendibite is an extremely rare silicate mineral that was first discovered in 1902 in Sri Lanka by Dunil Palitha Gunasekera and named after Serendib, the old Arabic name for Sri Lanka.

The mineral is found in skarns associated with boron metasomatism of carbonate rocks where intruded by granite. Minerals occurring with serendibite include diopside, spinel, phlogopite, scapolite, calcite, tremolite, apatite, grandidierite, sinhalite, hyalophane, uvite, pargasite, clinozoisite, forsterite, warwickite and graphite.