"5"^^ . "3"^^ . "Cave pearls are frequently found in disused adit leading bellow the \u0160pilberk Hill in Brno (Czech Republic). Each pearl consists of (1) a core comprised of an extraneous rock fragment and (2) a body organized into light and dark calcite layers. The number of the main layers roughly corresponds to 30 years of the total adit age. The darker layers occasionally show a sub-structure consisting of 2-3 extremely fine layers of various gray tones. Dendrite-like structures were observed in some cases. Conditions, necessary for pearl formation, were recognized as follows: (1) percolating waters supersaturated with respect to calcite, (2) free rock fragments as a basis for calcite nucleation, and (3) turbulent water circulation in dripwater pools preventing the fragments to fix at pool bottom during calcite growth. Initial bigger irregular rock fragments (10-15 mm in diameter) lead to formation of pearls of irregular shape. Tiny fragments (1-3 mm in diameter) lead to near spherical pearls." . . . . "%22Cave pearls%22 as a by-product of building constructions" . "P(GA205/03/1128), S, Z(MSM0021622412)" . "14310" . "%22Cave pearls%22 as a by-product of building constructions" . "Bu\u0159ival, Zbyn\u011Bk" . . "[0DED9433BDC9]" . . "Cave pearls are frequently found in disused adit leading bellow the \u0160pilberk Hill in Brno (Czech Republic). Each pearl consists of (1) a core comprised of an extraneous rock fragment and (2) a body organized into light and dark calcite layers. The number of the main layers roughly corresponds to 30 years of the total adit age. The darker layers occasionally show a sub-structure consisting of 2-3 extremely fine layers of various gray tones. Dendrite-like structures were observed in some cases. Conditions, necessary for pearl formation, were recognized as follows: (1) percolating waters supersaturated with respect to calcite, (2) free rock fragments as a basis for calcite nucleation, and (3) turbulent water circulation in dripwater pools preventing the fragments to fix at pool bottom during calcite growth. Initial bigger irregular rock fragments (10-15 mm in diameter) lead to formation of pearls of irregular shape. Tiny fragments (1-3 mm in diameter) lead to near spherical pearls."@en . "RIV/00216224:14310/08:00028038" . "\u0160telcl, Jind\u0159ich" . . . . . "SK - Slovensk\u00E1 republika" . "%22Cave pearls%22 as a by-product of building constructions"@en . . . . . . "Faimon, Ji\u0159\u00ED" . . . . "V\u00E1vra, V\u00E1clav" . "46" . . . . "%22Cave pearls%22 as a by-product of building constructions"@en . "adit; calcite; concrete; dripwater pool; percolating water; growth; microstructure; pearl; rock fragment"@en . . . "RIV/00216224:14310/08:00028038!RIV10-MSM-14310___" . "0560-3137" . . . "1" . . "Schwarzov\u00E1, Monika" . . "Slovensk\u00FD kras (Acta Carsologica Slovaca)" . "5"^^ . . "358955" . .