The chairman of Paragon Diamonds, Francesco 'Frank' Scolaro, has tightened his grip on the African gemstone group with the purchase of nearly £400,000 in shares.His Grandinex International Corporation took 1.29m shares at 30.47p a share taking Scolaro's total holding to about 123.4m shares, which is about 86.5% of the company.Paragon entered AIM in November. The shares were given a boost last week by news that Tamarisk Investments the Zambian subsidiary of International Diamond Consultants, in which Paragon holds a 44.3% interest, has been granted an exploration licence covering 862km2 in Eastern Zambia."The award of the KapLamp licence will add to our growing asset base and has provided Paragon with prospective opportunities given the established presence of recovered diamonds in a previously little understood structure type," Scolaro said after the announcement. "IDC is now prioritising targets within the licence area for further exploration utilising modern, exploration techniques."Top Director BuysParagon Diamonds (PRG) Director name: Mr Francesco (Frank) ScolaroAmount purchased: 1,290,000 @ 30.47p Value: £393,063Melrose Resources (MRS) Director name: Mr Robert F M AdairAmount purchased: 40,000 @ 230.00p Value: £92,000Melrose Resources (MRS) Director name: Mr Robert F M AdairAmount purchased: 22,000 @ 233.00p Value: £51,260Redstone (RED) Director name: Mr Richard Alexander McGregor RamsayAmount purchased: 3,481,200 @ 1.42p Value: £49,433Cenkos Securities (CNKS) Director name: Mr David HendersonAmount purchased: 30,000 @ 108.00p Value: £32,400YouGov (YOU) Director name: Mr Peter BazalgetteAmount purchased: 63,031 @ 47.00p Value: £29,625M. P. Evans Group (MPE) Director name: Mr P E Hadsley-ChaplinAmount purchased: 4,000 @ 490.00p Value: £19,600