198 GEMS AND PRECIOUS STONES IN THE
Fossil
corals, consisting of carbonate of lime, often possess great structural
beauty and are very compact and susceptible of high polish. Along the
shores of Little Traverse Bay, at Pe-toskey, Mich., are found
water-worn pieces of fossil coral of various species, ranging from
fragments the size of a small pebble to masses of 2 or 3 pounds weight.
The spaces or cells of these corals are entirely filled with carbonate
of lime, and being very compact, they take a fine polish. In color they
are of various shades of gray, and many of them are exceedÂingly
handsome. Visitors to Petoskey, which is a popular summer resort,
gather the corals, and to show the structure keep them in bottles of
water or give them a coat of varÂnish. The lapidaries of the place cut
and polish these corals, and at present probably $4,000 or $5,000 worth
are annually sold by them, either polished on one side, or in the form
of seals, charms, cuff-buttons, paper-weights, and other ornaments.
They are first ground on a Berea grindstone, then a polish is put on
with four successive grades of emery, and they are finally polished on
Spanish felt moistened with oxalic acid and lead ashes. The fossil
corals found near Dubuque and Iowa City, Iowa, are magnificent in color
and structure, and fine pieces often exceed a foot in width. They have
been used to some extent in jewelry, shaped into stones for cuff,
shirt, and vest buttons, the light cream-color making a very quiet,
rich stone for this purpose.
Pyrite
or sulphide of iron is found in many localities in the United States,
and one variety occurs in crusts or groups of small, brilliant crystals
with slate in the coal regions. These crusts are trimmed and cut into
ovals, squares, and other shapes, and sold for mounting as scarf-pins,
lace-pins, ear-rings, and ring-stones, as well as other ornaments. Fine
single crystals are also sold for ornaments, principally at Mauch Chunk
and the summit of the Switchback Railway, and by the local jewelers at
Ashland, Shenandoah, and Mahanoy City, in Schuylkill County, who obtain
their finest specimens from the Raven Run Mine, six miles from Mahanoy
City, Pa. Magnificent groups and fine single crystals with a very high
polish have been found at Black Hawk and other mines in Colorado and
sold for
