The Sea Glass Shard of the Month
A sea glass shard from a common electrical insulator.
January 2010
A Teal Sea Glass Shard from an Electrical Insulator
Sea Glass Specifications:
Color: Teal
Length: 47.0 mm (1.85")
Width: 27.2 mm (1.07")
Thickness: 21.1 mm (0.83")
Weight: 33.6 grams (1.19 ounces)
This fine sea glass specimen was found tumbling in the surf of Jamestown, Rhode Island near the historic Beavertail State Park. This teal color is commonly found in insulators along with aqua and white. Besides being very thick and chunky this piece of sea glass has the telltale threads that clearly indicate its origins before becoming a prized piece of sea glass.
The screw threads found on this sea glass shard were from an insulator design first developed in the 1860s.
These glass insulators were used in telegraph and telephone lines to prevent the wires from grounding out on the poles. The threaded design was developed in the mid 1860s to prevent the insulator from slipping off the wooden or metal pin that was then attached to the poles. These types of insulators were manufactured into the 1970s.
A detail of the screw threads of this sea glass shard.
Home to one of the oldest lighthouse locations in the country (the first lighthouse was built in 1749) the caretakers at Beavertail presumably had the need to communicate with the mainland. This sea glass shard was probably a discarded piece of refuse from one of the old telegraph or telephone poles in the area.
A still life of various sea glass shards along with the type of insulator that provided the sources for many of these gems.

