Gustavo Martinez worked for Hector Aguilar and was noted to be a friend of William Spratling. This bracelet is early and made in Mexico City as the hallmark shows the D.F. mark. The jeweled style was made well known and highly prized by Matilde Poulat. Also the hallmark reads COY which is an abbreviation for Coyocan which means "place of the coyote". The stones are with no chips or cracks. They are varied in tones of blue to dark green. The pictures show the more blue stones brighter than they really are. Please call with any questions and for a more complete description.