Chrysoprase and Jasper Collecting- Newfane, Vermont

by Jeremy Zolan

Outcrops around the town of Newfane have long been known for interesting samples of bright green chalcedony colored by nickel. This popular and beautiful semiprecious stone is known as chrysoprase. The majority of chrysoprase is mined from commercial lapidary rough mines in Australia, but fine examples of the material are also known from Poland, Albania, Kazakhstan, Tanzania, and Oregon. It is a relatively rare stone worldwide so having an opportunity to find it is certainly unique. In addition to chrysoprase, a variety of other beautiful material can be obtained at this site such as jasper, serpentine, and small quartz crystals. The rare hydrated nickel silicate garnierite has also been found here.

Chysoprase found in the streams of Newfane Vermont – Image courtesy of John Betts Fine Minerals

Chrysoprase forms from oxidized nickel impurities imparting a green color to the material. The source of this nickel is from rocks geologists call ultramafic. These ultramafic rocks were metamorphosed to form the serpentinite at the deposit. These rocks are from very deep in the earth and have a chemistry that differs quite a bit from other igneous rocks. Often these ultramafic rocks are very rich in magnesium, calcium, and iron. They are also frequently poor in silica and rich in elements like chromium and nickel. When these rocks are exposed to water as well as a tiny amount of heat ad pressure, they break down and form serpentinite. The metals leach into silica and other minerals giving them their color.

Collecting-

Most of the collecting at this site will be done in the stream, stream banks, or riverside outcrops. Collecting involves getting into the stream bank and flipping over rocks. You might want to bring a shovel or hand rake to remove material from the stream bottom. Inspect material carefully for anything interesting and keep an eye out for anything with a bright green color. Place anything you want to keep in a sturdy bucket. Heavy waterproof boots or waders are a must in colder months. When it’s warmer wear some waterproof shoes to protect your feet from the rough bottom. Bring a hammer and chisel in care you want to break open anything you find to inspect it further.

Directions-

Navigate to South Newfane and look for a bridge that crosses Adam’s Brook. It should be very close to the center of the small town. Find a safe place to park and enter the brook. Search material in the brook for minerals. There are serpentine boulders present. Nearby there are several outcrops near roadcuts along the brook that can also be dug for similar material. Always keep an eye out for a bright flash of green color.