A Large Alejandro Gomez and Rafael Tapia Mexican Leopard Opal and Silver Bust of the Aztec Warrior Cuauhtémoc, 20th century
Marks: F GOMEZ, TAXCO, MEXICO, 970, E TAPIA TAXCO
17-5/8 h x 10 w x 14 d inches (44.8 x 25.4 x 35.6 cm)

ILLUSTRATED:
Coenraads, Robert Raymond, and Alfonso Rosas Zenil. "LEOPARD OPAL: PLAY-OF-COLOR OPAL IN VESICULAR BASALT FROM ZIMAPÁN, HIDALGO STATE, MEXICO." Gems & Gemology, Winter 2006, p. 237.
"Leopard opal" is comprised of a vesicular basalt host permeated with play-of-color-opal, found only in the Zimapán region, Hidalgo State, Mexico. Long before the colonization of Mexico and Central America by Western nations, opal was mined by the indigenous cultures. The stone was described by the Aztec as quetza litzle pyolitli (bird of paradise stone) in relation to the constant movement of light playing on the surface of the mineral. Documented exportation of opals from Central America to Spain date as early as the 16th century, and a ring containing a "fire opal of Zimapán" can be observed in the Diego Velazquez portrait of Antonio Eusebio de Cubero. Another notable opal, El Águila Azteca (The Aztec Eagle), was discovered in an excavation in Mexico City around 1863 and is believed to have been part of the treasures of the Aztec ruler Moctezuma II (1502-1520.)

Many of the pre-Columbian mines were closed centuries ago and their locations lost, as Western nations focused mining efforts on more profitable precious metal ventures. However, in 1965 a prospector discovered a large opal deposit while fox hunting from which the opal in the present lot was discovered. At the time of the raw mineral's discovery, it was the largest single piece of opal ever discovered in the Sierra Madre Mountains in Mexico. The specimen was eventually acquired by Albert Eugene Upton, who decided to have the stone transformed into a historically relevant figure of Cuauhtémoc. The head was carved by Raphael Tapia from a raw 30,000 carat black basaltic leopard opal specimen over a period of seven months. Mounted in seven pounds of silver by the hand of Alejandro Gomez, the final stylized bust of Cuauhtémoc was displayed at mineral shows across the United States during the 1970s and 80s, on loan from Kansas Newman College.