ÅA N:o 1) Igneous Rocks of Sviatoy Noss in Transbaikalia. 61 
From this table it is easily seen that the pyroxene from 
the sviatonossite differs radically from the skarn pyroxenes 
being richer in Al;O03, Fe;03 and Na,O than any of the latter. 
Only the ratio MgO : FeO is one very commonly met with 
in the skarn-pyroxenes which often have nearly equal mole- 
cular amounts of ferrous oxide and magnesium oxide. On 
the other hand, our pyroxene takes its natural place among 
the variegated kinds of the magmatic pyroxenes, just as its 
optical properties are such as are often met with in these 
minerals. (Note e. g. the close agreement of analyses I and 
IIT!). 
Thus the pyroxene from the sviatonossite shares all the 
properties of the pyroxenes from igneous rocks of moderately 
- alkaline character. 
Titanite is the most abundant minor constituent of 
the sviatonossites. This mineral occurs in two generations: 
one in well-shaped crystals showing idiomorphic development 
towards all the other minerals. The crystals, however, are 
often broken up or rounded. Twinning is common. The 
colour of the mineral is pale chocolate-brown and the pro- 
> Pperties such as are normal to this mineral. 
The other generation of titanite occurs as frequent inclu- 
 sions in the andradite, being its alteration-product, as already 
— set forth. These inclusions are anhedral and in other respects 
have the same properties as the original titanite. 
A patiteis also rather abundant, often in the form 
of large rounded prisms, chiefly distributed among the mafic 
minerals, pyroxene and garnet, and as inclusions in these. 
Magnetite occurs chiefly as irregularly shaped inclu- 
— sions in the garnet and pyroxene. Occasionally larger and 
— idiomorphic crystals are met with in the granular feldspar 
mass. | | 
| Epidote. In these more alkaline sviatonossites the 
= epidote occurs chiefly in the form of inclusions in the garnet 
and pyroxene, but is occasionally also met with apart from 
these. Itis often accompanied by brown strongly pleochroic 
oo orthite, forming cores around which the epidote has 
— — crystallized. The epidote minerals are in these rocks far less 
T FEK PST PEST FE < 
