C=Spiney Oyster Shell SET 23 x 14 x 2mm 15 CT.
D=Serphanite 26 x 20 x 5mm 20 CT.
A=Pink lip mother of pearl 22 x 13 x 3.5mm 10 CT.
B=NV. Pilot Mountain Turquoise 16 x 12 x 2mm 10 CT.