This matched pair is cut from charoite from Siberia, Russia.   It was hand cut in my cutting shop.  The polish is good the edges are cut for setting the stone in a bezel and the bottoms are flat. THERE IS BLACK BACKING ON THE BACKS OF THESE STONES.  VERY NICE PAIR.

SIZE:(in millimeters) 20 x 18 x 3.5 MM THICK EACH STONE.
WEIGHT(Carats): 20 TOTAL WEIGHT OF BOTH STONES. 
DOME: SLIGHTLY DOMED.
BOTTOM: FLAT.  
EDGE:  GOOD FOR BEZEL 
POLISH:  GOOD.