bultfonteinite

例句：

1. 1. The diamond is the most valuable gem in the world.
   钻石是世界上最珍贵的宝石。
2. 2.She wore a beautiful necklace made of rubies and sapphires.
   她戴着一串由红宝石和蓝宝石制成的美丽的项链。
3. 3.The ancient city was buried under tons of rubble from the volcanic eruption.
   这个古老的城市被火山爆发后的大量碎石所埋没。