The drilling hit "more than 105m of high grade zinc and copper" within four intervals, including 16.5m at 10.2% zinc, 0.26% copper and 0.17 grams per tonne gold (plus silver and indium) from 316m.
The company is working towards a JORC 2012 compliant resource, with non-compliant estimates being a higher grade core of 16.5 million tonnes grading 6.3% zinc, 0.3% copper and 33 grams per tonne indium.
Capital markets firm Argonaut was cautious on the metallurgical implications.
"The variability of metals throughout this hole demonstrates the complexity of the West Desert deposit mineralisation," Argonaut said.
"Definition of detailed metallurgical domains will be key to efficient extraction."
American West listed last December after a A$12 million IPO.
Shares in the company were up 42% to 22c in morning trade, capitalising it at about $40 million.
