hellanditen.
/ˈhɛlᵻndʌɪt/, U.S. /ˈhɛlənˌdaɪt/ Mineralogy.
Any of a group of minerals found as brownish-red prismatic crystals in pegmatite veins in Norway and other localities including parts of Canada and California.Hellandites are hydrous borosilicates of rare earth elements and calcium, also containing aluminium, manganese, and iron, (Ca, REE, Th)6 (Al, Fe+3) Si4B4O22(OH)4 (where REE = rare earth element). Crystal system: monoclinic.
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the world > the earth > minerals > types of mineral > silicates > miscellaneous silicates > [noun] > cerite > cerium or rare earth silicates
tritomite1856
rinkite1885
hellandite1903
nordite1941
perrierite1951
spencite1961
tundrite1965
tritomite-Y1966
1903 Jrnl. Chem. Soc. 84 ii. 657 Both in crystalline form and chemical composition, hellandite is analogous to guarinite.
1924 J. W. Mellor Comprehensive Treat. Inorg. & Theoret. Chem. V. 512 Brownish-red hellandite from Lindvikskollan near Kragerö, Norway.
1964 Mineral. Abstr. 16 644/2 Hellandite is a boro-silicate with more than 10% B2O3 in addition to the known major constituents.
1987 Geothermics 16 137 Harkerite is not the only borosilicate found in the Sabatini district. Incompatible element bearing minerals such as a thorium-rich hellandite..have been recently reported.
This entry has been updated (OED Third Edition, June 2008; most recently modified version published online March 2022).
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n.1903