鏡面生鐵

thumb|upright=1.25|Spiegeleisen Spiegeleisen (literally "mirror-iron", —mirror or specular; —iron) is a ferromanganese alloy containing approximately 15% manganese and small quantities of carbon and silicon. Spiegeleisen is sometimes also referred to as specular pig iron, Spiegel iron, just Spiegel, or Bisalloy.