Miargyrite is an uncommon silver sulfosalt. Though opaque and with a metallic luster, it may have slight translucent overtones of dark red, especially when containing arsenic in its structure which can replace some of the antimony. Arsenic is responsible for lightening up the color, and when the arsenic fully replaces the antimony, the mineral is no longer Miargyrite, but Smithite, a rare sulfosalt with a bright red color and transparency. Miargyrite is named after the Greek word Meion - "less", and Argyros - "silver", since it contains a lesser percentage silver than other silver ores such as Pyrargyrite.