Scorodite (English spelling)

Japanese: スコロダイト（英語表記）scorodite

Also called scorodite. A type of hydrous iron arsenate mineral that is dark green. Its chemical composition is Fe ³⁺ AsO ₄ ･2H ₂ O. Fe ^{3+ and Al 3+} ^are mutually substituted to form a solid solution. The Al end member of this solid solution is called mansfieldite. Scorodite belongs to the orthorhombic crystal system and forms crystals that are close to octahedrons, but it often forms a film-like structure consisting of an aggregate of granular and needle-shaped crystals. It has a specific gravity of 3.3 and a Mohs hardness of 3.5 to 4. Its color ranges from dark green to gray-green, yellowish brown, and gray-green. Due to its somewhat high refractive index, the crystals may exhibit a subdiamond luster.

Source: Heibonsha World Encyclopedia, 2nd Edition Information

Japanese:

ソウ臭石ともいう。暗緑色を呈する含水ヒ酸鉄鉱物の一種。化学成分はFe^3＋AsO₄･2H₂O。Fe^3＋はAl^3＋と相互に置換し固溶体をつくる。この固溶体のAl端成分をマンスフィールダイトmansfielditeと呼ぶ。スコロダイトは斜方晶系に属し八面体に近い結晶となるが，粒状，針状結晶の集合した皮膜状となる場合も多い。比重3.3，モース硬度3.5～4。暗緑～灰緑色，黄褐色，灰緑色。やや高い屈折率のため結晶は亜ダイヤモンド光沢を示す場合がある。

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