The Vancouver-headquartered company said Tuesday cyanide leach analysis of five drill holes from the California porphyry gold-copper prospect had returned "excellent" gold recoveries of up to 87% gold and 45% silver over 98m in hole 18CER007.

A 106m-long intercept in hole 18CER006 returned gold recoveries of 84% gold and 54% silver, while a 93.5m intercept in hole 17CER003 recovered 84% gold and 49% silver.

The company noted silver recoveries of about 50% were considered normal for most oxide gold deposits, as silver had slower leach kinetics compared to gold.

"We are very happy to see such high gold recoveries using the ALS-Chemex cyanide leach analysis, a clear indication that the precious metals in the gold oxide cap of this newly discovered porphyry gold-copper system are amenable to leach processing," said CEO Joy Wilkins.

He said the team planned to conduct more detailed metallurgical test work on both leach and flotation recoveries in order to more fully unlock the mineral potential of the California zone.

Aztec said the sulphide mineralisation also returned significant cyanide leach results, such as 52% gold recovery in hole 18CER015 and 73% gold recovery in hole 18CER010 over 40m.

The company said lower cyanide leach gold recoveries were recorded in ore with higher levels of copper sulphide enrichment, but noted that this type of mineralisation represented only about 20% of the overall California zone.

The C$4.23 million company is trading 40% lower than a year ago at 15c, having peaked at 38c in March.