"褐色闪光矿物" can be translated as "brown shiny mineral" or "brown lustrous mineral" in English.
Here, "shiny" or "lustrous" both convey the idea of something having a bright or reflective surface, which aligns with the "闪光" (shǎn guāng, meaning "shining" or "glittering") in the Chinese term. "Brown" directly corresponds to "褐色" (hè sè, meaning "brown"). "Mineral" remains the same in both languages to refer to a naturally occurring, inorganic solid with a definite chemical composition and an ordered internal structure.