One Cabochon.  Calibrated.

 

Natural Blue Lace Agate, 40x30mm size.   B Grade. Soft cornflower denim blue with varied striping

 

(Picture 1  is a representative picture, each piece will have natural variances.) The other pictures are the actual stones available, and you may choose, if there are multiples.

 

Great to bead around, make into a brooch.