Revija Prirodoslovnega muzeja Slovenije - Prirodoslovni muzej ...

Miha JERŠEK, Marjan DOLENC: Zbirke mineralov, rud in kamnin Marjana DolencaSummaryIn his successful professional career of economic geologist and professional ore and mineralsearcher, Marjan Dolenc managed to gather a significant systematic collection of minerals, oresand rocks. As he travelled a great deal and worked abroad, he gathered most of the samples byhimself, while some of them were bestowed on him by his friends and colleagues who were wellacquainted with his passion for collecting. He assembled his mineral, ore and rock samples in sixdifferent collections: 1. Collection of Minerals, 2. Rock Minerals, 3. Mineral and Ore Deposits,4. Petrographic Collection, 5. Geological Phenomena, and 6. Gem Stones. In 2011, he donated thecollections to the Slovenian Natural History Museum, but left the collection of gem stones to hisclosest relatives.At the very beginning of his collecting career, Marjan Dolenc solved the eternal spatial problemin mineral collecting. Specifically, he decided that his samples would all be up to 43 x 30 mmlarge. But as there were no suitable little boxes to be found, he decided to make them by himself.Using his own system, he was thus able to keep more than 2,000 samples in two showcases. As thecollections are arranged systematically, he saved some place for the missing samples in the firstthree collections, although only for more significant minerals and rocks.In the first collection, i.e. the systematic collection of minerals, Marjan Dolenc gathered a widerange of known as well as fairly rare minerals. In this collection, they are separated according tothe systematics of (1) native elements, (2) sulphides, (3) haloids, (4) oxides, hydroxides, (5) nitrates,carbonates and borates, (6) sulphates, chromates, molybdates and wolframates, (7) phosphates,arsenates and vanadates, (8) silicates, and (9) organic matter. As Marjan Dolenc believed thatcertain minerals were discriminated in certain systematic collections, he established the collectionentitled Rock Minerals with main rock-forming minerals, accompanying and accessible mineralsas well as »accidental admixtures. The third collection is dedicated to deposits and associations ofminerals and ores that occur in separate deposits. Apart from numerous deposits from Macedoniaand Africa, the collection of perlites and carbonatites should be mentioned as well. Althoughcarbonatites, in particular, are relatively rare rocks, Marjan Dolenc managed to gather quite few ofthem. The petrographic collection reveals the great diversity of rocks and rock-forming minerals.The collection embraces magmatic, sedimentary, metamorphic and pyroclastic rocks, togetherwith the characteristic minerals. In the collection Geological Phenomena, on the other hand, someinteresting minerals and rocks, which arouse special interest due to their forms or freaks of nature,can be found.151