38 . Pentti Eskola. = = (CSA 
perties of the baikalite from the south shore of Lake Baikal, 
which, in fact, occurs in quite the same kind of pegmatite. 2 
This mineral often shows fine euhedral development. The = 
end planes usually are ill developed or wanting. All around = 
the pyroxene there are smaller prisms of a pale green 2 
amphibole in which the angle c:y = 20 and o=B 
= yellowish <y = pale greenish. This amphibole no doubt é 4 
represents a product of alteration of the pyroxene at an TN 
early stage. 
Titanite is, in the diopside-pegmatite, always present 
in considerable amounts and as large crystals. In many 
cases it assumes the character of an ordinary constituent 
whose amount may equal or exceed that of all the other 
constituents. | 
Another rather abundant accessory mineral is a p a tite. 
Small crystals of ort hite also occur frequently. 
A further very remarkable feature of this pegmatite is 
the frequent occurrence of graphite which is present in SN 
the form of thin scales. 
It is apparent alone from the RA of this : 2 
pegmatite that its occurrence has a close relation to the = = 
limestones of this region, as all its characteristic minerals 
are lime-bearing. And, as already mentioned, it is found 
only where limestone occurs, while elsewhere the pegmatites 
always are of the common kind. In Finland also similar 
pegmatites often occur in connection with limestones, e.g. = - 
..1n the quarries of Kirmonniemi in Korpo, studied by A. Laita- 
kari ?) and at many localities in southwestern Finland inves- Sd 
tigated by myself. "Especially in the parish of Lohja, where 
limestone forms a rather extensive area, have I found peg- 
matites very closely resembling the diopside-pegmatites in — 
Transbaikalia. In most of these Finnish occurrences the 
abundance of titanite is as remarkable as in the diopside- 
pegmatite of Sviatoy Noss. The occurrence of graphite in 
the latter is of: Se a special interest and no doubt referable 3 
; VC . é . I : be . . ; . : . vå +) la 
1) Aarne Laitakari, »Le gisement de calcaire cristallin de Kirmonniemt - 
ä Korpo en Finlande» Bull; Comm. géol. Finl, 46 p. 22. 
