Well this is interesting and the Amethyst Mineral Kingdom would like to explain.

这很有趣，紫水晶矿物王国很愿意就此来解释。

youdao

The colours changed from green to amethyst.

这些颜色从绿色变成了淡紫色。

《柯林斯英汉双解大词典》

Amethyst is the birthstone for an Aquarian born in February and garnet for an Aquarian born in January.

生于二月的水瓶座人的诞生石是紫水晶，而生于一月的水瓶座人的诞生石是石榴石。

youdao

The Maritime and Coastguard Agency said the Amethyst's crew made proper use of their life-saving equipment.

BBC: Three fishermen rescued after boat hits rocks near Skye

Does the shape of the amethyst look like a dragon or a poodle to your guests?

FORBES: If Facebook Delivers (Or Disappoints), Try Minerals

The "amethyst mountain" is a massive ridge that stretches away northwest of Tafraoute.

BBC: Trekking the unexplored mountains of Morocco