clambroth

From clam +‎ broth.

clambroth (plural clambroths)

1. A kind of marble with equally spaced opaque lines on a usually milk-white opaque base.
   • 1997, Miriam L. Plans, Caring for your antiques & collectibles, page 94:

     Rare marbles, especially overlays, sulphides, clambroths, and other unusual specimens, need gentle washing and drying.

• barmcloth