** Shares of Rarex Ltd REE.AX rise as much as 21.05% to A$0.023, their biggest intraday pct gain since May 9

** The critical minerals miner said drilling results at Cummins range confirm their estimates for Gallium at the Western Australia site in April

** Co says Cummins range is potentially Australia's highest grade and most advanced gallium deposit

** Stock touches its highest level since May 19

** Around 21.3 mln shares change hands, over 5x stock's 30-day avg of about 3.78 mln

** REE currently up 15.8%, bringing YTD gains to 144.4%

(Reporting by Shruti Agarwal in Bengaluru)

((Shruti.Agarwal@thomsonreuters.com))