THE COLLECTION OF MINERALS 
have gathered many minerals. Most of the species which have 
been found may be seen in the Collection (Case 27) of the New 
York Mineralogical Club. This collection is arranged to show, 
approximately, the minerals of the foliated schistose mica and 
hornblende rocks, the minerals of the granite veins, dikes and 
bosses and the minerals of the limestone beds. 
Beginning with the minerals of the mica rocks, very fine ex- 
amples of a yellow to brown Stilbite are noteworthy, the rosettes 
of flat blades lying upon the scaly surface of the gneiss or schist. 
With these are remarkable specimens of Chabazite, Epidote, 
Fibrolite, Harmotone, Heulandite and the interesting little 
spheres of Spherosiderite. The hornblende rock follows with 
superb flattened crystals of greenish Titanite imbedded in the 
black masses. The view taken by geologists of the hornblende 
rocks on Manhattan Island now is that they are the changed 
remains of former igneous intrusions, soft pasty lava-like dikes, 
entering the island beds. They are often associated with epidote. 
The hornblende rocks are well exposed near 135th Street and 
Amsterdam Avenue. 
The granite section shows a striking group of minerals, and it is 
in these granites—mostly veins or dikes—that the collector finds 
the richer collecting grounds. Here are Allanite (in long crys- 
tals as Orthite), Apatite, Beryl, Cyanite, Dumortierite (a rare 
mineral), Feldspars (Albite, Orthoclase, Oligoclase, Microcline), 
Micas (Muscovite, Biotite), Garnet (note particularly the superb 
example from West 35th Street), Magnetite, Monazite (a rare 
mineral containing cerium, didymium, lanthanum and thorium), 
Ripidolite, Tourmaline (big, splendid black crystals in Quartz), 
Wernerite and Xenotime (another rare mineral containing 
yttrium, erbium, cerium and thorium). 
The last group of minerals belongs to the limestone beds, and 
here are pretty bunches of Smoky Quartz crystals, brown Tour- 
malines and white Pyroxene (Malacolite) with peculiar veinlets 
of fibrous Aragonite. 
Another area (the serpentine) yields examples of an inter- 
mixture of Calcite (Dolomite) and Serpentine, forming a speckled 
rock called (incorrectly) Ophiocalcite. More striking specimens 
of this can be seen in Case I of the Geological Hall. 
There are several mineralogical surprises in the collection, 
for example: Galenite (sulphide of lead) in minute cubes on 
Chabazite, Gypsum in radiating prisms on mica rock, Fluorite 
(large block from the Subway), Iolite (Pinite), Zircon, Uraninite 
(the chief mineral containing radium). 
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