Mar 26—History Alive! featured tables laden with rocks, seemingly formed at the beginning of time. Steve Schuchman's mineral collection was varied and fascinating. On display were large and small specimens from many geologic eras. Steve was inspired to collect by discovering agates in his grandparents’ driveway in Woodburn, Oregon. His grandparents, who homesteaded around 1916 in Oregon, lived “over the hill” from a gold mine. They turned up a great many interesting minerals, which a young Steve found incredible. His parents had a gift shop on Highway 44 in the 1940s near Grace Lake Resort, where his father sold gift items made from Manzanita and other woods. Steve grew up loving woodworking and other crafts, and especially the geology inspired by the volcanics of Mount Lassen and the surrounding area.
With a wealth of geologic information gleaned from numerous college classes, and a working knowledge of the Russian language from graduate study in Russian Literature and a summer in Russia in 1973, Steve traveled the world, spending much time in Russia working with other collectors to amass a variety of unique specimens. He eventually opened his own rock shop in McDermitt, Nevada, near one of the richer deposits of gemstone materials in North America. He has attended The Tucson Gem and Mineral Show, in Tucson, Arizona (said to be the largest, oldest and most prestigious gem and mineral show in the world) annually since the 1970s, where he gets reacquainted with rock-hound friends from around the US, Russia and many other countries around the world.
Steve emphasized that prized rock formations can take millions of years to form, and are usually only exposed after much erosion has taken place. Minerals found in the Mt. Lassen area volcanics are too recent to reveal the gemstone materials such as agate, jasper, opal and petrified wood that are forming in volcanics at depth. Locally, there is a lot of obsidian in our area, particularly in the Warner Mountains, because it forms during the fast cooling in the wake of a volcanic eruption. Nearby collecting areas are numerous however, particularly in Nevada and Oregon, including in The Black Rock Desert in Nevada; in Southeastern Oregon just north of McDermitt, Nevada; in Southeastern Oregon near Burns; in Northcentral Oregon near Madras; and in the Ochoco Mountains of Oregon.
As for the difference between a Geode and a Thunderegg: a geode is a general term for a crystal-lined cavity that can form in a variety of geologic environments - inside a thunderegg; inside an agate formed in an ancient volcanic gas pocket; inside sedimentary rocks, such as a fossilized coral in Florida - as the interior dissolves away and is replaced with crystals.
A Thunderegg, the official state rock of Oregon, is formed as radiating, primarily cristobalite, crystals grow out from centers within a slowly cooling rhyolitic extrusive igneous magma. The temperatures of the magma are high enough that it is semi-plastic, and a cavity often forms within the center of the growing semi spherical cristobalite mass as magmatic gasses come out of solution. The cavity forms within the Thunderegg mass because the pressure caused by the escaping gasses initially open between the weakest molecular bonds within the semi-plastic magma, which happen to be between the radiating fibrous crystals of cristobalite. This often-star-shaped cavity, because of secondary hydrothermal activity associated with the volcanism, may or may not later fill with mineral crystals of some sort: agate, jasper, moss agate, plume agate, siderite, zeolites, calcite, etc. If the cavity is left open, with crystals inside, the Thunderegg itself would be called a geode. An agate without a cavity inside is called a nodule.
Steve showed us many examples of the different forms of agate, as well as rocks from Ethiopia, Africa, Russian, Brazil and Peru. He had a beautiful, large, pink specimen of Peruvian opal. He identified the many purple amethyst crystals which were on display as quartz crystals, with manganese impurities that caused the purple color. Steve also told us about one of the best rock museums in the area - Gaumer’s Mineral & Mining Museum, in Red Bluff, which showcases over 100 years and four generations of collecting.
Those interested in collecting, or learning more, can contact the Shasta Gem and Mineral Society, and participate in field trips. Unfortunately, most gold on the east side of the Sacramento Valley in our area will not be on the surface, as it was buried by the relatively recent volcanic action, but some petrified wood can be found in Cow Creek near Millville. (Please do not enter private property without permission). Gold has been found west of Redding, and there are many collecting areas in the California Coast Ranges and Siskiyou County for semiprecious gemstones such as jasper, agate, jade, petrified wood, as well as fossils.
Steve also looked at a couple of collections brought by attendees and helped identify several specimens.
Wanted: People with a lively curiosity & an interest in local history. No experience necessary. Training provided. Call Beverly 1-530-474-5110