Koba Resources (ASX:KOB) jumped 20% in the second hour of trades on Tuesday as the company flagged the results of its latest uranium-containing rock-chip-hunting campaign – which resulted in one sample grading over 7%, or, more than 70,000ppm. There’s been a lot of rock-chip news from explorers lately – more than what was the case six months ago, which you’ll just have to take my word for (I read a lot of announcements in this line of work). I presume because it’s cheaper than drilling as inflationary pressures remain a headwind for explorers. Rockchip-based announcements can be dicey, given s…