Occurrence Thundereggs are found globally where conditions are optimal. In the US, eastern Oregon is one of the most famous thunderegg locations. There are many beds open to the public to dig, but most of them charge a nominal fee. One can also obtain a map from the USGS to find public land that is open for digging. Germany is also an important center for thunderegg agates (especially sites like St Egidien and Gehlberg). Other places known for thundereggs include Ethiopia, Poland, Romania, Turkey, Mexico, Argentina, Canada, Mount Hay and Tamborine Mountain, (Australia) and the Esterel massif, (France). Formation Thundereggs are found in flows of rhyolite lava. They form in the lava from the action of water percolating through the porous rock carrying silica in solution. The deposits lined and filled the cavity, first with a darker matrix material, then an inner core of agate or chalcedony. The various colors come from differences in the minerals found in the soil and rock that the water has moved through.Thunderegg Oregon State Rock, StateSymbols USAThe interior and exterior colors can vary depending on where the thunderegg is found. It is very common to dig them in one bed and then go to a different bed half a mile a way and the eggs look completely different. Some thundereggs have moss in the agate and others have plants in the agate. Those plants are called "plume" and those eggs are very desirable since it is not a common occurrence. State rock designation On March 30, 1965, the thunderegg was designated as the Oregon state rock by a joint resolution of the Oregon Legislative Assembly.Chapter 186 — State Emblems; State Boundary 2017 Oregon Revised Statutes While thundereggs can be collected all over Oregon, the largest deposits are found in Crook, Jefferson, Malheur, Wasco and Wheeler counties. The world's largest thunderegg, a 1.75 ton specimen, is housed by the Rice Northwest Museum of Rocks and Minerals in Oregon .Many of the thundereggs found in Oregon have agate inside that resembles the shape of the state of Oregon when cut .
Occurrence Thundereggs are found globally where conditions are optimal. In the US, Oregon is one of the most famous thunderegg locations. Germany is also an important center for thunderegg agates (especially sites like St Egidien and Gehlberg). Other places known for thundereggs include Ethiopia, Poland, Romania, Turkey, Mexico, Argentina, Canada, Mount Hay and Tamborine Mountain, (Australia) and the Esterel massif, (France). Formation Thundereggs are found in flows of rhyolite lava. They form in the lava from the action of water percolating through the porous rock carrying silica in solution. The deposits lined and filled the cavity, first with a darker matrix material, then an inner core of agate or chalcedony. The various colors come from differences in the minerals found in the soil and rock that the water has moved through.Thunderegg Oregon State Rock, StateSymbols USA State rock designation On March 30, 1965, the thunderegg was designated as the Oregon state rock by a joint resolution of the Oregon Legislative Assembly.Chapter 186 — State Emblems; State Boundary 2017 Oregon Revised Statutes While thundereggs can be collected all over Oregon, the largest deposits are found in Crook, Jefferson, Malheur, Wasco and Wheeler counties. The world's largest thunderegg, a 1.75 ton specimen, is housed by the Rice Northwest Museum of Rocks and Minerals in Oregon .
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eastern
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There are many beds open to the public to dig, but most of them charge a nominal fee. One can also obtain a map from the USGS to find public land that is open for digging.
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USAThe interior and exterior colors can vary depending on where the thunderegg is found. It is very common to dig them in one bed and then go to a different bed half a mile a way and the eggs look completely different. Some thundereggs have moss in the agate and others have plants in the agate. Those plants are called "plume" and those eggs are very desirable since it is not a common occurrence.
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.Many of the thundereggs found in Oregon have agate inside that resembles the shape of the state of Oregon when cut