Guess which ASX 300 lithium stock just rocketed 30% on a ‘significant milestone’

The S&P/ASX 300 Index (ASX: XKO) is up a happy 0.5% today, but this ASX lithium stock is leaving those gains far behind.

Shares in the emerging lithium–boron producer closed up 15.6% to end yesterday trading for 18.5 cents. In morning trade on Friday, shares just…