Calcite    Guanajuato, Mexico.  Ex. Nancy Collins collection.  The original dealer tag has this as “dolomite calcite xls” but I only see calcite.  The odd stripe on the center of each calcite should also be calcite but I have not tested it.  In any case, the piece is 9.2 x 5.6 x 5 cm.  It is an unusual thing with the gray centrally located band being translucent to transparent and the white body of each crystal being nearly opaque.  There is no damage to the piece and it sits and displays nicely.  $160