A hydrous silicate mineral rich in Fe and containing small amounts of Al and Mg. Its chemical composition is (K,Na,Ca)(Fe3 + , Fe2 + , Mg,Al) 12 (Si,Al) 18 (O,OH ) 54 ・ nH2O . Some types are mainly Fe2+ and others are mainly Fe3 + . Triclinic crystal system. It has a complex layered structure. It has fine black leaflets and resembles biotite, but is more brittle than mica, with slightly incomplete basal cleavage and some perpendicular cleavage. Mohs hardness 3-4, specific gravity 2.6-3. Source: Heibonsha World Encyclopedia, 2nd Edition Information |
Feに富み,少量のAl,Mgなどを含む含水ケイ酸塩鉱物。化学組成は(K,Na,Ca)(Fe3+,Fe2+,Mg,Al)12(Si,Al)18(O,OH)54・nH2Oで表される。Fe2+を主とするものとFe3+を主とするものがある。三斜晶系。複雑な層状構造をもつ。黒色の微細な葉片状をなし,黒雲母に似るが,雲母よりもろく,底面のへき開はやや不完全で,これに直交するへき開もある。モース硬度3~4,比重2.6~3。
出典 株式会社平凡社世界大百科事典 第2版について 情報 |
…This is a ceremony that marks the newborn baby...
Among cultivated plants of the Poaceae family, su...
In chemistry, chemical synthesis, or simply synth...
A general term for animals belonging to the order...
…It is also linked to Morpheus, the god of dreams...
…Gliders usually do not have propulsors, and ther...
…A mountain range in central Italy, about 20 km s...
〘 noun 〙 Cotton imported from a foreign country. I...
〘noun〙 (odds)① Advantageous conditions given to th...
…The transverse groove just before the cervical r...
…[Nobuyuki Ueda]. … *Some of the terminology that...
A small island in the southern part of the Indian ...
An adventure spy novel (1980) by American author R...
A collection of abstracts from the records of the ...
A power generating dam located on the Mimikawa Riv...