The present criteria which basaltoids for petrurgical*purposes should meet are generally regarded as being associated with thequalitative and quantitative parameters of their chemical and mineralogicalcomposition. However, in petrurgical practice one can observe the phenomenonthat rocks with virtually identical compositions show variable technologicalproperties during the melting and subsequent processing. This is also the caseof alkaline olivine basalt and nepheline basanite from the Bileice locality (12km SE of Bruntal) used in the manufacture of rockwool. This variability ofpetrurgic properties, shown in spite of a relatively very stable chemical andmineralogical composition of the raw material, was the reason why the rocks weresubject to a detailed petrographic and geochemical study. This study resulted inthe finding that in assessing the raw materials for petrurgical processingaccording to their chemical and mineralogical composition, attention should alsobe paid to the textural and structural characteristics of the respective rocks.
