Mineral exploration firm Red Rock Resources said on Thursday that Resource Star, in which it holds a 15.2% stake, had exercised its option to acquire an Australian cloud computing service.Australian-listed Resource Star announced it had reached a deal to purchase Cloud Lands Digital Fortress, though the acquisition remained conditional upon a number of terms, including the completion of a capital raising of A$3m.On Thursday, Red Rock shares closed 11.82% up at 0.190p.