PYRITE IN
DOLOSTONE
Dolostone is a chemical sedimentary rock
composed of dolomite (CaMg(CO3)2 - calcium magnesium
carbonate). It is usually
gray-colored, finely-crystalline, and often has irregularly-sized &
irregularly-shaped holes called vugs. The dolostone shown below has a sucrosic
(sugary) texture with abundant, relatively small vugs, plus beautiful,
brassy-colored pyrite crystals that line part of a large vug (reportedly
a ~2 foot-diameter subspherical cavity).
Pyrite is iron sulfide (FeS2) and many of these crystals have
colorful-iridescent oxidation films.
Stratigraphy & age: Lockport Dolostone (ÒLockport
DolomiteÓ), upper Niagaran Series (upper Wenlockian), upper Middle Silurian
Locality: sidewall of open-pit quarry, ~300Õ below
the surface, National Lime & Stone CompanyÕs Buckland Quarry, just
southwest of the town of Buckland, northern Moulton Township, northern Auglaize
County, northwestern Ohio, USA.
Pyrite crystals on sucrosic dolostone (above & below)
from the Lockport Dolostone at Buckland Quarry, northwestern Ohio, USA.
