Rox said the latest results from the Grace project had returned "exceptional" results.
New results included 8m at 37.25 grams per tonne gold from 44m, including 4m at 73.81gpt and 4m at 9.96gpt; 4m at 18.06gpt gold from 16; 4m at 11.02gpt gold from 48m; and 4m at 5.13gpt gold from 12m.
The results are interpreted to be close to true width and define a series of moderate west-dipping quartz-hosted gold lodes in granite that remain open at depth and along strike.
The drilling identified new gold-bearing veins above and below the Grace lode that are yet to be tested.
Rox managing director Alex Passmore said reverse circulation drilling was set to restart later this week, followed by diamond drilling.
"The results demonstrate the high prospectivity of the Younami project area beyond previously identified ore zones," he said.
Each company holds 50% of the joint venture, but Rox has the potential to move to 70%.
Youanmi has a resource of 12.4 million tonnes at 2.97gpt gold for 1.19 million ounces and historically produced 670,000oz at 5.4gpt.
Shares in Rox jumped 12% to A2.8c, while Venus was up 5.9% to 18c.
