Some of the most eye-catching fossils I have ever seen are the blood-red solitary rugose corals (horn corals) belonging to genus Lophophyllidium of Pennsylvanian age (approx. 308 m.y. old) from a locale in the Morgan Formation in the Wasatch Mountains, east of Salt Lake City, Utah. Many of these horn corals from this locality have had their calcareous exoskeletons replaced, in part or nearly completely, by jasper. Thus these fossils are commonly referred to as “jasperized horn corals.” Another common moniker is “agatized corals.” These specimens are coveted by collectors and especially those who make jewelry.
|Lophophyllidium sp., Pennsylvanian, Utah,|
8.5 cm length, 4.5 cm width.
|6 cm length, 4 cm width.|
|Top view of specimen shown to the left;|
width 4 cm.