144 FIELD CoLUMBIAN MusEUuM—GEoLoGy, VoL. III. 
terize the Joplin calcites, as described by one of the authors.* 
The average development of the forms is shown in the accom- 
panying figure, Fig. 2. The planes of the different forms show 
readily recognizable: peculiarities. Thus the planes of v (2131) 
usually have brilliant, more or less undulating surfaces, those of 7 
(1011) are roughened like ground glass, and those of w (3145) are 
smooth. The substance of the crystals is semi-transparent and 
amethystine in color. Needles and flakes of marcasite are included 
in large numbers through the substance. Fragments of the calcite 
phosphoresce with a warm yellow light when moderately heated, 
although Headdenj+ found only the yellow Joplin calcite phosphor- 
escent. The largest crystals measure a foot in length and weigh 
20-30 lbs. 
MEARC Ie 
BELLEVUE; OHIO 
FIG. 1, PLATE XLIX 
A crystal of calcite (Mus. No. M 10372) kindly presented to the 
Museum by Mr. 8. A. Kurtz, Principal of the Bellevue High School, 
shows some unusual features. The crystal is of the ‘“dog-tooth”’ form 
and would appear on casual glance to be a polar half of a scalenohed- 
ron. It is 2.5 cm. in length and composed of colorless, transparent 
calcite. Mr. Kurtz states that such crystals occur at a depth of about 
twenty feet from the surface ina hard, blue layer of the Niagara lime- 
stone at Bellevue. An examination of the crystal with the reflecting 
goniometer shows that its fundamental forms are not scalenc ~ Jrons 
but pyramids of the second order. The dominant one of these 1s 7 
(8.8.16.3). This, it is of interest to note, was found by Penfield and 
Ford to be a dominant form on silicious calcite from the Bad 
Lands, Nebraska,t and Union Springs, New York.§ Rogers also 
found it a dominant form on calcite from Shullsburg, Wisconsin.|| 
The next pyramid of the Bellevue specimen cuts the vertical axis at 
one half the height of 7, its symbol being « (4483). Above this occurs 
the pyramid z (1123) cutting the vertical axis at one fourth the height 
of 4. The pyramids are thus in Dana’s symbols, 4,°-2, §-2 and 3-2. 
* Farrington, Pub. Field Col. Mus., 1900, Geal. Ser. Vol. I, pp. 232-241. 
t Am. Jour. Sci., 1906, 4, 21, p. 301. 
+ Am: Jour. Siex900, 4,.0; 0. 353: 
§ Am. Jour. Sci., 1900, 4, 10, p. 237. The Union Springs occurrence was further studied by 
Whitlock (Bull. 908, New York State Museum) and the conclusion reached that the pyramidal 
habit was produced by crystallization from a highly siliceous solution. 
| Am, Jour. Sci., roor, 4, ¥2, p. 42. 
