Scientific American 49, 26.8.1848
The following particulars relative to this beautiful blue pigment, were lately published by the Petersburg Academy of Sciences. Lapis Lazuli are found in all the rivers that fall from Khamardaban, but mineralogists have not yet succeeded in finding its flow notwithstanding the minute researches which have been made in divers points. Mr. Moor the mineralogist, who spent two summers on the banks of the Hindianka, succeeded only in discovering the flow of glaucolithe, or calcareous blue spath, - and every attempt since made to ascertain the place of formation of the lapis lazuli has been unsuccessful. The natives affirm that this precious stone is met with after the heavy rains have washed down the pebbles found in the beds of the rivers. Mica, is found in great abundance in the neighborhood of Hindianka, in the form of not very thick flakes, lying upon a bed of soft clay as if it had been deposited upon it. The inhabitants frequently resort to these places to carry of the mica - which they put into their window-frames in place of glass.