Curiosities at Fort Stanwix: A Herkimer Diamond, a Horn Coral and a Victorian Playhouse

The museum collection at Fort Stanwix National Monument in Rome, New York, holds nearly 500,000 objects. Among them are natural history pieces found in archeological excavations in the early 1970s. Some were identified correctly at the time; others were misidentified — archeologists study human material culture, and don't generally have the training to identify geological specimens. The geological finds fall into three groups: curiosities, building materials and sediments. Here are two of the more unusual curiosities.

A Herkimer diamond

A Herkimer diamond — a quartz crystal pointed at both ends. Fort Stanwix National Monument Museum Collection, FOST 11521. NPS Photo.

Catalogued as a cut or worked piece of crystal, this is in fact a natural quartz (SiO₂) crystal — a fine "Herkimer diamond," a quartz crystal naturally shaped with a pyramid at each end.

• Herkimer diamonds formed as groundwater seeped through buried dolomitic sandstone of the Little Falls formation. The Little Falls Dolostone began in a shallow shoreline setting, was buried for millions of years, and was compressed into rock.
• Such crystals are fairly uncommon, found and collected locally near Middleville, New York. The first scientific descriptions date from 1819 and 1823.

A horn coral

A fossil horn coral. Fort Stanwix National Monument Museum Collection, FOST 11522. NPS Photo.

This fossil horn coral — also called rugose coral — likely formed in shale of the Skaneateles Formation, Hamilton Group, of Middle Devonian age, about 400 million years ago. In New York these fossils are most often found along the east shore of Skaneateles Lake. Horn corals lived on shallow, warm, marine shelves, like a tropical seabed below the reach of waves.

Why "curiosities"?

Both objects turned up near the back of the Kingsley family home on Liberty Street.

• Dr. Willey Kingsley bought the house in 1861 and remodeled it for his growing family in 1870. Two sons, George and Willey J., survived infancy; both became doctors like their father.
• An 1878 image of the property shows a two-story playhouse in the back yard. According to a 1972 history of the site, it had an inside stairway to a second floor with built-in display cases, reportedly used by the boys for their rock and mineral collections and aquariums.

The Kingsley playhouse, before it was moved off the site during the reconstruction of Fort Stanwix. NPS Photo.

Could the Herkimer diamond and the horn coral have been treasures from the boys' collections, shared with friends and played with in the yard?

Sources

Based on "'Curiosities' & Natural History Objects," part of the series Curious Collections of Fort Stanwix, The 19th & 20th Centuries, Fort Stanwix National Monument, National Park Service; a work of the United States government in the public domain. Its sources include L. Beck, Mineralogy of New York (1842); Y. W. Isachsen and others, Geology of New York (2000); B. Mason and L. G. Berry, Elements of Mineralogy; B. S. Moore, Herkimer Diamonds (1989); and D. S. Waite, History of a 19th Century Urban Complex on the Site of Fort Stanwix (1972). The article dates Mason and Berry to 1967 in one place and 1965 in another.