The 32.5 million tonnes grading 1850 parts per million lithium for 60,300t of contained lithium (or 320,800t lithium carbonate equivalent) was estimated 14 months after drilling started.
The drilling included 40 diamond core holes totalling nearly 3000m.
A Phoenix-based engineer has been appointed to assess the prefeasibility process.
Earlier this year Hawkestone appointed lithium expert Dr David Deak as its advisor.
"Sediment-hosted, clay-based lithium projects present a unicorn opportunity for Hawkstone," Deak said at the time.
"Once in production, a sediment-hosted lithium project can bend the lithium cost curve, as it represents a potential easily-pittable, low-cost mining operation with low energy and cost footprint."
Hawkstone is estimated to have about A$1 million cash.
Shares in Hawkstone were up 7% to 1.5c in morning trade capitalising the company at $8.5 million.