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Post by Admin on Jul 7, 2022 8:55:00 GMT -7
Hi, I'm 1dave of RTH. An RTHer! RTH is A Fantastic Place to learn about ROCKS - HOW AND WHERE TO FIND THEM & WHAT TO DO WITH THEM
 I was born in 1936, so at the moment of this writing I am 85. I live in ENOCH, Iron County, UTAH, so this area is my usual playground.   Here are a few of my favorite things: Lithophasa, Thundereggs, TE2, Gem Stones, Opal, Fire Agate, Fire Agate Veins, Turquoise, Geodes, Dinosaur Bone, Petrified Wood, Agate/Jasper, And my favorite places: Australian Opal, The Petrified Forest, Ruby Hills, San Raphael Swell, Vernon Utah, Mineral Mountain, Bryan Head, The Hurricane Cliffs, Iron County Iron Mines, Holt Canyon, |
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Post by Admin on Aug 3, 2023 8:20:52 GMT -7
I was born during the Great Depression, became an air force Brat, moved from base to base, . . . Ended up in 3rd grade in Austin Texas at the end of WWII. My teacher had a huge iron pyrite cube on her desk. I was caught! 1955 I started studying geology at BYU. 1957-1960 in Uruguay, land of the HUGE amethyst geodes! mymodernmet.com/large-amethyst-geodes/ 1960 - returned to Orem Utah, wired new home for Bob Rollins. He offered to teach me lapidary and silver smithing in exchange for wiring his rock shop. ACCEPTED! 1961 Happily Married, worked as a master electrician, mostly coal fired powerhouses all over Utah, some time in Nevada, Boston. Retired 1999, moved to Cedar City Utah, played with rocks. |
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Post by Admin on Aug 3, 2023 8:22:43 GMT -7
Oh My Dave , now THAT'S a geode ! Patty
Yes, BUT same time, nearly same place, Uruguay:  Basalt was flowing much slower, bubbles collected much larger. crystals grew on agate layer. Later large calcite crystals grew. Brazil:   Basalt was flowing much faster, bubbles are smaller. Groundwater was much different. For long periods the groundwater slowly converted the basalt bubble walls to green celadonite that fell to the floor. Then the agate rapidly coated the walls in multiple thin layers. I suspect shockwaves! Then the large crystals grew. Radioactive elements converted iron from citrine to amethyst. Last, calcite crystals grew. |
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Post by Admin on Aug 3, 2023 8:37:28 GMT -7
You're always pushing me Dave, 1dave to sit up and learn about rocks ! So I need to look it up but.... Does amethyst always need a radioactive element to form ? Patty Yes, and iron. Hither and yon Iron atoms take the place of silicon, turning the crystal yellow ( and making Brazil Twins). Radiation (usually from uranium) notches the iron to change from yellow to purple. If you put the amethyst crystals in an oven at ~450 degrees F they will revert back to citrine.  |
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Post by Admin on Aug 3, 2023 9:49:10 GMT -7
WAY cool, 1dave I think that Geode needs a hinge so you could keep it closed until you wanted to impress someone. And that would keep the dust out anwyay! So now that we're picking your brain- Does amethyst retain residual radioactivity ? Patty  |
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