Post by 1dave on Sept 7, 2020 12:12:34 GMT -7
Agate is the rock most often appreciated and worked with by rockhounds.
What information of it's history (HINT- began at outside bottom and exterior, worked from outer shell to the center. Notice entrance and exit points!) can YOU deduce?
A few of the more obvious changes numbered in green.
1. first arrivals - grow into plumes, tubes, etc.
2. multiple bands of moganite, chalcedony and quartzine adhering to all outer walls ("fortification agate")
3. a few tiny layers of "waterline agate"
4. a few more bands of chalcedony (re-heated by another eruption?)
5. layers of blue waterline agate
6. a lens of quartz crystals (mostly re-dissolved)
7. quartz crystals clinging to all walls (again mostly re-dissolved)
8. different colored fortification agate entering from multiple points, each with different minerals providing different colors. Note how each new fill dissolved different portions of previous fills, changing the shape of the remaining inner chamber!
EDIT: (from further down the thread)
Here is a puzzle for you.
I found this image of a Scottish "pebble" on "Meaning of Agate."
What information of it's history (HINT- began at outside bottom and exterior, worked from outer shell to the center. Notice entrance and exit points!) can YOU deduce?
A few of the more obvious changes numbered in green.
1. first arrivals - grow into plumes, tubes, etc.
2. multiple bands of moganite, chalcedony and quartzine adhering to all outer walls ("fortification agate")
3. a few tiny layers of "waterline agate"
4. a few more bands of chalcedony (re-heated by another eruption?)
5. layers of blue waterline agate
6. a lens of quartz crystals (mostly re-dissolved)
7. quartz crystals clinging to all walls (again mostly re-dissolved)
8. different colored fortification agate entering from multiple points, each with different minerals providing different colors. Note how each new fill dissolved different portions of previous fills, changing the shape of the remaining inner chamber!
EDIT: (from further down the thread)
If you want to know about Agate Two members of this site (Lowell @elementary - and Mel @sabre52) have contributed The agate index!
www.4shared.com/office/mNXTQALM/Agate_Index_Vol_1__2nd_ed_.html
www.4shared.com/office/pe4TRDLx/Agate_Index_Vol_2.html
www.4shared.com/office/Df_uL8jg/Agate_Index_Vol_3.html
www.4shared.com/office/oCLei3tU/Agate_Index_Vol_5.html
www.4shared.com/office/XplaNpW1/Agate_Index_Vol_7.html
www.4shared.com/office/mNXTQALM/Agate_Index_Vol_1__2nd_ed_.html
www.4shared.com/office/pe4TRDLx/Agate_Index_Vol_2.html
www.4shared.com/office/Df_uL8jg/Agate_Index_Vol_3.html
www.4shared.com/office/oCLei3tU/Agate_Index_Vol_5.html
www.4shared.com/office/XplaNpW1/Agate_Index_Vol_7.html
