Sudbury Basin-Ontario-making my case because I am a stubborn cuss....

The basin formed as an impact from a bolide approximately 10–15 km (6.2–9.3 mi) in diameter that occurred 1.849 billion years ago^[2] in the Paleoproterozoic era.

 

Debris from the impact was scattered over an area of 1,600,000 km² (620,000 sq mi) and traveled over 800 km (500 mi) away — rock fragments ejected by the impact have been found as far as Minnesota ^[3] (though models suggest that for such a large impact, debris was most likely scattered globally,^[4] but has since been eroded away). Its present size is believed to be a smaller portion of a 250 km (160 mi) round crater that the bolide originally created.

Help us identify Mystery Rock-dum dum dum (dramatic music)!

Carol's Etsy description says 

"The pendant is from a rock we aquired when we bought 3 cigar boxes of rocks that came from an estate sale. The rock is moss agate, the mystery are the metalic circular inclusions. I did some research and these may be iron concresions of some sort or lapilli. If you've seen this before contact us I would love to know for sure."

 

I, not being a geologist, looked up Lapilli and found on Wiki that Lapilli is a size classification term for tephra, which is material that falls out of the air during a volcanic eruption or during some meteorite impacts.^[1] Lapilli (singular: lapillus) means "little stones" in Latin.

 

What we hypothesize is that these lapilli flew through the air getting all roundy in the process, eventually falling to Earth.  Later a Quartz/Chalcedony solution enveloped these balls.  When the whole rock was cut into slabs the spheres became circular cross sections.  The cigar boxes of rocks came from an older gentleman who lived in Rochester, MN, but it is hard to know where this was collected.  I think it was collected from Northern Minnesota and that it originated from a meteor impact in Southern Ontario from a time I can't remember (I read about at the Minnesota Geological Society website).  Carol believes the spheres came from volcanic action.  She is probably right, but heck, we may both be wrong, so any help on this is appreciated.  No reward only credit on the blog and the everlasting glory that brings!

Northfield Riverwalk Market

Today we were at the Northfield Riverwalk Market selling our jewlery and cabochons.  The day was much sunnier than last time, when we got dumped on with a deluge of rain.  It was muggy and hot and we had a fun time talking with the people who came by to look or to buy.  Some were jewelry makers or had tumbled a rock or two in their day.  

Jim was in good spirits.  He had been in the hospital for a few days and had just been released yesterday (Friday 7/15).  I was surpised he wanted to come.  We had a lot of fun!!

General Store and Rock Shop in Oakaton, SD-Honeymoon Memories

Oakaton, SD General Store and Rock Shop

The old Oakaton Feed Mill



Carol and I were on our Honeymoon traveling to Utah via I-90 through South Dakota.  We had gotten married in June of 2005 and I believe the Honeymoon trip was late June- early July.  We had not hit the Black Hills and I spotted this obscure sign that said Rock Shop next Exit.  I turned instinctively in the turn lane (not telling Carol what I was doing, only that it was "An adventure").  There was the sign for Oakaton, SD pop. 12 at that time.  What a charming semi-ghost town.  The general store used to have a much better rock shop back in the day, but evidently the husband and wife who had the place before had died and the rock selection had waned.  There were still nice specimens and a fair amount of fossils left, but the passion wasn't in the new owners.  The place had back buildings that showed what the place used to be like with an old bank, jail, blacksmith... and these spaces were filled with antiques for sale.  What was of more interest was the old run down feed mill with an abandoned set of Milwaukee Railroad tracks in front of it.  Evidently, the Milwaukee Road abandoned the track in the mid to late 1940's, but neglected to pull the rails.  As you can see by the picture, the cross bars are still there.  Years ago, someone from Hollywood came to Oakaton and filmed a movie that was never released.  This was a romantic trip and a very romantic stop.  Rocks, fossils, a single gas pump, old buildings, old set of train tracks set into the Dakota Prairie, and each other.  Meow.

Coming up on Oakaton from the north off I-90

Ancient Beauty - Mary Ellen Jasper

Mary Ellen Jasper comes from the Mary Ellen Mine in Minnesota.  Scientifically known as Collenia undosa, the microorganisms involved were likely to have been photosynthetic bacteria that were busily expiring oxygen that would ultimately constitute the modern atmosphere on earth during a time colloquially termed the “rusting of the earth”.



Polished Mary Ellen

 



Rough Mary Ellen

These microoganism colonies are called Stromatolites, these stony algae colonies built up layers and sometimes whole reefs.  Mary Ellen Jasper is the fossilized remains replaced in sedimentary rock, the beautiful filaments and layered polyps are one of the earliest life forms preserved today.  At over 2 billion years old, this primitive species is often credited with providing our oxygen rich environment.

You can still find Stromatolites today in such places as Shark Bay, Australia where they continue their billions of years old lifestyle.

Montana Moss Agate Treasures

Montana Moss Agate is the name given to the beautiful chalcedony found in the alluvial gavels of the Yellowstone River and its tributaries. It is From the Pleistocene age (10,000 - 1,6000,000) Found not in-site, but in gravel deposits.


A small area in Montana seems to have the best of this agate. Found in gravel deposits in the middle and lower Yellowstone valleys. Agates are found in both the present stream bed and in gravel terraces. 10 to 15 miles either side of the Yellowstone drainage. 

Rough                                                    Polished













Cabochons Jim has made from Montana Moss Agate

    

   

Hidden Treasure

Part of the joy of collecting is that you never know what you will find when you saw into the rock.  The rock shown above is cut from a piece Carol collected years ago from the dump piles of the Old Hickory Mine in Utah.  The Old Hickory mine was once mined for copper.  The dump piles contain rock deemed not worth much-namely the offshoots of copper like azurite, cuprite, and chrysocolla to name a few.

The rock I cut into had streaks of chrysocolla along with calcite (the green above is the chrysocolla and the white is calcite.  What I wasn't expecting was a copper based mineral called covellite.  Covellite is the blue and it has pyrite in it so you get the blue/gold shimmer.  Covellite is rare and increasingly sought after.  The best source was the old Leonard mine in Butte, Montana-which has been closed down since the early '70's.

It took awhile to realise what we had here.  This combination of minerals is atypical.  This is a heavy sucka due to the metal content-it will make a wonderful pendant for Carol.