1·Moreover, corundum and periclase have not been detected in space dust before.
而且，此前在太空尘埃中还未侦测到刚玉和方镁石。
2·Rubies, valued as precious gems, are the mineral corundum in its red form.
作为一种珍贵的宝石，红宝石是一种红色的矿物刚玉。
3·Ruby, the common name for the mineral corundum in its red form, is a precious gemstone.
红宝石是对红色矿物刚玉的俗称，它是一种珍贵的宝石。
4·At the same time, some of the same or higher hardness material, such as diamond, corundum, metal oxide, quartz crystals are likely to damage the material.
同时一些硬度相同或更高的物质，例如钻石、刚玉、氧化金属、石英水晶都有可能损坏这些材料。
5·The crystals were housed in magnificent Temples, some built of marble, others of crystalline sheets of beryl, corundum and diamond.
水晶被安置在宏伟的神殿里，一些为大理石建造，其他的由绿玉，刚玉，钻石建成。