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出典:Wiktionary
出典:『Wiktionary』 (2025/10/29 20:01 UTC 版)
polycrase (usually uncountable, plural polycrases)
出典:Wikipedia
出典:『Wikipedia』 (2010/11/29 22:01 UTC 版)
Polycrase or polycrase-(Y) is a black or brown metallic complex uranium yttrium oxide mineral with formula: (Y,Ca,Ce,U,Th)(Ti,Nb,Ta)2O6. It is amorphous. It has a Mohs hardness of 5 to 6 and a specific gravity of 5. It is radioactive due to its uranium content (around 6%). It occurs in granitic pegmatites.