The extreme end-products of selective crystallization (“ mother liquor’’) are 
frequently rich in quartz, in the elements that form soda-feldspar, in water 
vapor, dissolved gases and other mineralizers. 
Concentrated during selective freezing, these products may be distributed 
interstitially; they are generally not in equilibrium with the previously solidi- 
fied minerals of the parent rock and they attack these minerals, forming new 
minerals better adjusted to the existing conditions. When such processes 
are aay mineralization, sometimes of economic importance, frequently 
results. 
Fig. 1 “ Deuterized” granite. The interstitial matter here is quartz and 
albite; albite attacked the potash-bearing feldspar along the margins and 
has injected it in wavy stringers. The pyroxene of this rock has likewise 
been attacked, the products being talc and serpentine. 
Figs. 2 and 3. Ore from the Canopus mine. In fig. 2, the feldspar has 
been affected by end-stage product, (deuteric action) injected with albite 
(white streaks) and partly sericitized. In fig. 3 the feldspar has been almost 
wholly sericitized. This action was intimately connected with mineralization ; 
the magnetite (black) is replacing the rock by these magmatic end-stage 
processes, 
Fig. 4 Epidote gneiss (granitized Pochuck-Grenville) in the vicinity of the 
Canopus mine, illustrating injection effects on the country rock. All taken 
in polarized light, nicols crossed: fig. 1 magnified 35 diameters, figs. 2, 3 and 
4 magnified 65 diameters. 
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