A field term used to describe a light-colored, mica, usually in metamorphic rocks, such as muscovite and margarite, and also illite, phengite, and celadonite.
A field term used to describe a light-colored, mica, usually in metamorphic rocks, such as muscovite and margarite, and also illite, phengite, and celadonite.
Any ceramic that fires to a white or ivory color, commonly used in wall tiles, tableware, etc.
Willemseite is the Ni-rich (Ni > Mg) member of the talc group. Willemseite occurs at Barberton Mountain Land, Transvaal.
An obsolete local, varietal term for antigorite serpentine of various colors, but typically green, from West Chester, Chester County, Pennsylvania, USA.
A member of the palygorskite-sepiolite group with a composition of approximately (Ca1.68Mn0.32)Fe3+2.96(Si7.87 Al0.08)O20(OH)4. 10H1.98O.
See palygorskite-sepiolite group
An obsolete varietal term for biotite.
See pyroxenoid group.
A trioctahedral mica that shows interlayer deficiency. It is a series name (Rieder et al., 1998) with a generalized composition of Na0.5v0.5Mg2.5Al0.5(AlSi3)O10(OH)2, where = vacancy The formula indicates that it is not an end-member composition. Series names designate that additional research may be warranted.
See hydrotalcite group.
An obsolete varietal term for biotite.