Cordierite (English spelling)

Japanese: キン青石(菫青石) - きんせいせき（英語表記）cordierite

Cordierite is a rock-forming mineral that is found widely in contact metamorphic rocks of pelitic origin and in regional metamorphic rocks of relatively low pressure. It can also be found in _{granite, pegmatite, andesite, and their xenoliths. Its chemical composition is (Mg,Fe)2Al4Si5O18} _. It belongs to the _orthorhombic crystal system, has a specific gravity of 2.53-2.78, a Mohs hardness _of 7, and a characteristic light blue to dark blue or purple color. It is found in chunks or granules, and rarely as hexagonal short columnar crystals, with unclear cleavage. It often forms multiple twins, and in pelitic rocks, the boundaries between three twins are sometimes decomposed, and the hexagonal cross section is shaped like a cherry blossom, and it is commonly called cherry blossom stone.

Source: Heibonsha World Encyclopedia, 2nd Edition Information

Japanese:

コーディエライトともいう。泥質岩起源の接触変成岩や比較的低圧の広域変成岩に広く出現する造岩鉱物の一つ。花コウ岩，ペグマタイト，安山岩やその捕獲岩にも含まれていることがある。化学組成は(Mg,Fe)₂Al₄Si₅O₁₈。斜方晶系に属し，比重2.53～2.78，モース硬度7，特徴的な淡青色から濃青色または紫色を呈する。へき開は不明瞭，塊状ないし粒状，まれに六角短柱状結晶として産出する。多片双晶をなすことが多く，泥質岩中には時に三つの双晶の境が変質分解し，六角形の断面が桜の花のような形を示すことがあり，俗に桜石と呼ぶことがある。

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

<<: Golden Saint Lament - Golden Saint Lament

>>: Kim Sǒng-su (English spelling)