鉄てつ石せき英えい

noun

ferruginous quartz

Technical term in mineralogy for quartz containing iron impurities, often with a reddish or brownish color.

• この標ひょう本ほんは鉄てつ石せき英えいで、鉄てつ分ぶんによって赤あかみを帯おびている。

  This specimen is ferruginous quartz, and it has a reddish tint due to iron content.