The stone is buried stone, but stone hardness up to 7 or more, its unique is famous for making stone rockery stone.

该石虽属地埋石，但石质硬度较高可达7级以上，其独特之处是制作假山石材的著名石种。

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As the carbon content in steel increases up to around 0.60%, the possible hardness obtainable also increases.

随着钢的含碳量增加到大约0.60%，可能得到的硬度也增加。

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For other purposes, its hardness and strength can BE improved by adding various amounts (up to 12%) of antimony alone.

对于其他用途来说，只消在铅中加进不同量的锑(不超过12%)，就可提高其硬度和强度。

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