Mineral name. Chemical composition: ZrO 2 . Monoclinic columnar or table-shaped crystals. Usually twinned. Completely cleaved at {001}. Colorless and transparent, but brown to black due to the presence of trace elements. Mohs hardness: 6.5, specific gravity: 5.8. High melting point of 2715°C, low thermal conductivity. High refractive index of 2.1 or more. Transforms to tetragonal at 1 atmosphere and about 1100°C, reducing volume. Zirconium (Zr) is more abundant in the earth's crust than copper, but it is commonly produced as zircon (ZrSiO 4) , and baddeleyite is an extremely rare mineral. Source: Heibonsha World Encyclopedia, 2nd Edition Information |
鉱物名。化学組成ZrO2。単斜晶系で柱状・卓状結晶。通常は双晶になっている。{001}でへき開完全。無色透明であるが,微量成分の存在で褐色~黒色を呈する。モース硬度6.5,比重5.8。2715℃の高融点を有し,熱伝導度は小さい。屈折率は2.1以上と高い。1気圧,約1100℃で正方晶系に変態し,体積が減少する。ジルコニウムZrの地殻存在度は銅より多いが,ジルコンZrSiO4として一般に産出し,バデレアイトは非常にまれな鉱物である。
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 |
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