macedonite (rock)

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Macedonite is a non-porphyritic, basaltic-looking rock and in the annotated copy is said to "consist largely of minute felspars, a colour-less to green interstitial mineral, either glass or chlorite, serpentine or chlorite pseudomorphs after olivine, some light-brown biotite and purplish, fibrous apatite prisms. Octahedra of perofskite occur, some of which are opaque, others of a dark grayish-green colour. The exact relations of this rock are difficult to determine. Chemically it is in some respects intermediate between the tephrites and the orthoclase basalts, but mineralogically it is quite distinct. Its nearest relations are with the mugearites, from which it differs in the ratio of soda to potash and in the small amount of olivine present." The writer does not say what kind of feldspar is present, but if the analysis is computed in the Quantitative System of C.I.P.W., the norm shows orthoclase, 20.02 percent, albite, 29.87 percent, and anorthite, 18.63 percent. As computed by the reviewer the rock is a Shoshonose.