031918, 170301, 260302, 260317, 261709, 261713, 270305 - Shells, including sand dollars, nautilus, conch shells and scallop shells. Stones for jewelry (cut or uncut), nuggets of precious metal. Plain single line ovals. Concentric ovals and ovals within ovals. Curved line(s), band(s) or bar(s). Letters or words underlined and/or overlined by one or more strokes or lines. Representations of objects forming letters or numerals, including punctuation.