MINING exploration company Noble Minerals made a tentative debut on the Johannesburg bourse on Friday, weighed by investors taking profits on the listing and a slightly weaker resources sector. Noble, which has diamond and manganese exploration projects in two provinces, first traded at 50c — 5c above the price at which shares were issued to investors ahead of the firm going public. But the stock, quickly slumped as low as 19c before clawing back to 38c, where it was hovering at 1100. An analyst said that the slow start — only 640000 counters had traded so far — may also be due to investor caution about mining exploration projects which by nature have a risk element.