sandcalcite

例句：

1. 1. Sand and calcite are the main components of sandstone.
   沙和方解石是砂岩的主要组成部分。
2. 2.The mineralogist studied the chemical composition of sandcalcite.
   矿物学家研究了方解石的化学成分。
3. 3. The crystal structure of sandcalcite is unique and has been studied extensively.
   方解石的晶体结构独特，已被广泛研究。