Mushrooms may be what people think of when they think of Morgan
Hill, but jewelers and geologists have something else in mind:
Poppy jasper. And further south, keep your eyes out for benitoite,
discovered in and named after San Benito County.
Mushrooms may be what people think of when they think of Morgan Hill, but jewelers and geologists have something else in mind: Poppy jasper. And further south, keep your eyes out for benitoite, discovered in and named after San Benito County.
Poppy jasper is unique to the area and was made Morgan Hill’s official stone in May 2002. A 62-pound sample of the rock is on display at the Community and Cultural Center on Dunne Avenue and Monterey Road.
Peter Anderson, the principal geologist with Pacific GeoTechnical Engineering in Morgan Hill, says jasper comes in different forms. Morgan Hill’s version is characterized by concentric rings as well as the poppy orange color which gives it its name.
“It its believed Morgan Hill is the only place in the world where poppy jasper has an orange color,” Anderson says. “It’s probably true.”
Poppy jasper is classified as an orbicular, or ringed jasper. It was created when, millions of years ago, fissures formed deep beneath the earth’s surface, causing fluid with silicon dioxide to seep in. As time went on, the fluid solidified and formed into a substance similar to quartz. The gem rose to the surface over millennia as the mountains formed.
The color comes from impurities that were in the fluid, Anderson says. Iron oxide mixed with it and created different colors depending on the atomic structure of the iron.
Morgan Hill’s unique stone is often crafted into jewelry. Gene Donlan, owner of Top-A Rock Shop in San Juan Bautista, cuts poppy jasper into different shapes, usually with a “cabechon,” or flat and smooth back.
“We cut the stone as big as possible to maximize the quality of the rock we’re working with,” Donlan, who sets the gem in silver, says.
His silver pieces can cost from as little as $50 up to several hundred dollars.
Poppy jasper is primarily found in the Santa Cruz Mountains region. Around Morgan Hill, the stone has been found near El Toro, Hayes Valley and in a bedrock ridge to the south-east of the city. All locations are on private property, so weekend gem-hunters had better watch out.
Meanwhile, just down the road, benitoite was discovered in 1907 in the south county. The only mine was worked for decades by Bill Forrest, who sold it to Collector’s Edge Minerals, Inc. in Golden Colorado a few years ago.
