Excerpt from The Journal of Geology, Vol. 7: July August, 1899

The vague spheres of feldspar often have an imperfect black cross in polarized light, and consist mainly of orthoclase, some what turbid and specked with brown iron oxide, with a little of the green mineral intermixed. The rest of the rock contains some orthoclase also, but consists chie¿y of the isotropic substance inclosing the radiating bundles of prisms referred to before. The green prisms are fresh in color and appearance, and are usually distinctly dichroic, dark green when the prism IS parallel to the chief section of the nicol, yellowish-green at right angles to this position. Extinction is nearly parallel, but angles of occur. The larger crystals sometimes have sharpened ends, The mineral was at first taken for hornblende, but is no doubt aegyrite.

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