noun, noun which may take the genitive case particle 'no', na-adjective
metallic quality; mineral matter
Refers to the property of being metallic or containing metal/minerals. Used as a noun or adjectivally with な/の.
この石は金属質の光沢がある。
This stone has a metallic luster.
土壌に金属質な成分が含まれている。
The soil contains mineral components.
Compound of 金属 (metal) and 質 (quality, matter). The exact historical derivation is uncertain, but the word transparently means 'metallic quality' or 'mineral matter'.