Karelian Diamond Resources plc announced that the Company has received notification from the Finnish Safety and Chemicals Agency (Tukes) of the granting of an extension for a further 3 years, the maximum period allowed per extension to the Company's exploration permits Riihivaara 26, Riihivaara 24, 24a and 24b in the Kuhmo region of Eastern Finland. The Riihivaara 26 exploration permit covers Karelian Diamond's kimberlite (olivine lamproite) discovery at Riihivaara. Exploration permits Riihivaara 24, 24a and 24b cover the adjacent areas.

The Riihivaara permits are in an emerging kimberlite field, in which the Company has to date identified 20 regional anomalies. The Company's kimberlite discovery at Riihivaara is circa 10 kilometres to the south of where the Company discovered a green diamond. As announced on 19 December 2023, the search for the source of the green diamond has recently been narrowed down quite substantially through recent work undertaken by Karelian Diamonds.

The Riihivaara kimberlite comes to surface and extends for at least 350 metres. It is a dyke which remains open in both directions along strike with widths of up to two metres intersected. Drilling has already successfully intersected kimberlite at a deeper level and has also shown that the dyke dips at circa 50° to the Northeast.

Mineral chemistry at the site shows that diamond indicator Group I eclogitic garnets are abundant and that diamond type chromites are also present. Ilmenite analysis indicates a good diamond preservation index. Mineral chemistry also shows that more than one source may be present.

It is known that kimberlites tend to occur in clusters and that potentially diamondiferous sources may exist in the vicinity of the Riihivaara kimberlite. To this end Karelian Diamonds has also extended the Riihivaara 24, 24A and 24Bexploration permits. The Company believes the Kuhmo region of Finland has high prospectivity for diamondiferous kimberlites both through its own exploration results in the Kuhmo region, including the discovery of a green diamond, and also by the presence of the Seitaperä diamondiferous kimberlite, circa 8 kilometres to the northwest of Riihivaara, which Karelian Diamonds has shown to extend over a surface area of 6.9Ha - the largest known kimberlite in Finland.