Malmikaivos Oy, a small Finnish copper mining company, initiated diamond exploration in the 1980's after discovering a train of kimberlite glacial boulders. Malmikaivos Oy established a joint venture with the Australian company Ashton Mining Ltd. in 1986 and in 1994 Malmikaivos Oy became fully owned by Ashton. Ashton’s countrywide regional sampling program has identified several separate and distinct areas in Finland from which kimberlite indicator minerals are sourced. Ashton has discovered 24 kimberlites and related rocks in Finland and 16 of these are now known to be diamond bearing. The main kimberlite clusters are located in Kaavi and close to the city of Kuopio in eastern Finland. Mini-bulk samples have been taken from five of the diamond bearing pipes. At least two of the more closely studied pipes contain substantial quantities of clear and colorless diamonds. A 23 tonne sample from a pipe of approximately two hectares in surface area yielded some 26 carats of +0.8 mm diamonds per 100 tonnes, most of which were of good quality. Another pipe, slightly over one hectare in size, contained 13 to 26 carats per hundred tonnes, based on a 9.4 tonne sample.
Dia Met Minerals Ltd. (AMEX, TSE, VSE), which has been operating in Finland through Oy Alwima Ltd., announced in February 11, 1998 that in addition to continuing exploration on its 100-per-cent-owned Finland project, an agreement has been reached to enter into a joint venture with Ashton Mining Limited on Ashton's Finland diamond project. The joint venture covers two areas in eastern Finland, one of 38,475 sq-km and the other of 40,750 sq-km. Follow-up sampling has identified indicator mineral trains in these areas, in addition to those that Dia Met had already discovered. The joint venture has recently discovered the 25th kimberlitic body at Viitasalo, and drilling has proceeded throughout the winter (Ashton 1998 Annual Report).
Other companies involved in diamond exploration in Finland include RTZ Mining & Exploration Ltd, Finsearch Oy ( De Beers), Glenmore Highlands Inc. (ASE), Conroy P.l.c., North Star Diamonds A.S. (Poplar Resources Inc., VSE), Baltic Minerals Finland Oy, America Mineral Fields Inc. (TSE) and Archangel Diamond Corp. These companies have not released any information concerning their success. The Geological Survey of Finland (GTK) is not engaged in diamond exploration but rather offers sampling, sample processing and other exploration services for diamond exploration companies, and undertakes regional heavy mineral surveys. GTK undertakes such grass-roots activities to increase exploration interest in Finland.
Over 80% of Finland has been flown by Geological Survey of Finland airborne geophysical surveys, with raw and processed magnetic and EM data readily available, based on survey line spacings of 200 m and a terrain clearance of 30–40 m. Bedrock and surficial geological mapping also covers a large part of the country at scales of 1:100,000 or better, and most data are available in numerical form.
Collaboration with Finnish universities and the EUROPROBE program has also provided comprehensive information concerning late Archean and early Proterozoic tectonic evolution and deep crustal and lithospheric structure, based on seismic, electric and thermal modelling.
Conditions in Finland are also very favourable with respect to infrastructure, mining legislation and land tenure. Reconnaissance exploration permits can be issued over extensive areas, allowing regional appraisals to be made for up to a year prior to lodging a specific claim application. Although such permits do not grant exclusive access to the area in question, they do establish priority when making subsequent exploration or mining claims. At present, exploration and mining leases, as opposed to reconnaissance permits, cover only about 0.2% of the country.