This American News Company marble is yellow-gold with grey veining.
Two more Balances in black and yellow-green marble are shown with an unidentified all-white marble pencil.
An earlier Sheaffer bell-top pencil from the 1920s (below) shows a fine-textured type marble in emerald green, very attractive on this large, weighty, rear-drive example.
Of course, there is also this kind of marble, named for the stone they resemble, but made of glass.
And finally, the biggest marble of them all.
Something to ponder.