The Collaborative International Dictionary
fire marble
Lumachel \Lu"ma*chel\, Lumachella \Lu`ma*chel"la\, 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.
Wiktionary
fire marble
n. lumachel
Usage examples of "fire marble".
Slowly Anna reached out and took the fire marble from his hand, holding it up, she dropped it suddenly into the bowl of water at her side.