lumachella

{ ‖ } n. [ F. lumachelle, It. lumachella, fr. lamachella a little snail, dim. of lumaca a snail, fr. L. limax, -acis. ] (Min.) A grayish brown limestone, containing fossil shells, which reflect a beautiful play of colors. It is also called fire marble, from its fiery reflections. [ 1913 Webster ]