3 sentences

1. 这里的晶体形状非常规则。

   zhè​lǐ de jīng​tǐ xíng​zhuàng fēi​cháng guī​zé.

   The shapes of the crystals here are very regular.

   Source: Dong Chinese Dictionary

2. 这种晶体被称为薄荷脑，闻起来很凉。

   zhè zhǒng jīng​tǐ bèi chēng​wéi bò​he nǎo, wén qi​lai hěn liáng.

   This crystal is called menthol; it smells very cooling.

   Source: Dong Chinese Dictionary

3. 这种矿石是由许多微小的晶体组成的。

   zhè zhǒng kuàng​shí shì yóu xǔ​duō wēi​xiǎo de jīng​tǐ zǔ​chéng de.

   This mineral is composed of many tiny crystals.

   Source: Dong Chinese Dictionary