** Shares of Australia's Redcastle Resources RC1.AX rise as much as 21.9% to A$0.195, their biggest intraday pct gain since Jan. 28
** Stock hits highest level since Feb. 13
** Diversified miner says it has transitioned from gold explorer to producer
** Says move follows commencement of mining operations at its Queen Alexandra and Redcastle Reef gold deposits in Australia
** "We believe this delivers exceptional leverage to gold fo our shareholders," Non-Executive Chairman Ray Shaw says
** YTD, stock up 92.7%
(Reporting by Aamir Sheik Khalid in Bengaluru)
((Aamir.SheikKhalid@thomsonreuters.com))