Washington State Basaltic Obsidian or Tachylytic Obsidian

This is the first piece of "Basaltic Obsidian" that I found. It was found on 08/18/02.  It was found near an area called the Whiskey Dick Mountains

These samples (Bottom 3) were found on 04/25/09  North of the original find. The large light blue piece is my original find.

Found 04/25/09

Close up of the material under the patination

On June 30th 2009 while rock hounding with my son Adam. We weren't specifically look for the Blue when he yells out "HEY DAD" come here I found some Blue rock.

Almost 7 years after the first find we finally found the source of the Blue rock. I'd like to give my son Adam credit for finding the spot.

Still not knowing what the material was we just called it "Blue Obsidian"

Still fascinated with the finds and wanting to find some more

 we headed out on October 3rd 2009 to hunt for some more Blue.

Trying to find our original spot we weren't having much luck. When all of a sudden we started to find some isolated fractured nodules.

We decided to separate to cover more territory. For the better part of an hour all we we finding were fractured nodules.

 When I found this beautiful specimen. Weighing in at 255 grams and measuring 87mm X 59mm X 43mm

 Here are a few close-ups of the surface of the Nodule

Insitu of a nice nodule

36mm X 29mm X 21mm

And the Adam find his Specimen

Weighing in at 119 grams

61mm X 50mm X 42mm

The total haul of fractured nodules

These samples were sent to Craig E. Skinner at the Northwest Research Obsidian Studies Lab for Identification and analysis.

On 10/09/09 I received this email from Craig.

      
I'm all finished up with the XRF analysis of the Parke Creek samples and it looks like you've found a brand-new source - it's clearly

 a different geochemical type than the nearby Stray Gulch material. 

See the attached PDF for a copy of the analytical results and a scatter plot that illustrates the differences between the two sources. 

BTW, the reason that I can tell that these are a tachylyte (basaltic composition) rather the more typical rhyolitic composition of most obsidians are the very elevated quantities of Ti (titanium) and Fe2O3 (Iron). 

For obsidian, the typical numbers would be more like 1000 ppm for Ti and 1-2 percent for Fe.

Thanks again for sending these and I'll be sure to give you credit if I ever publish the results somewhere. 

For now, your new source will be immortalized at: <http://www.sourcecatalog.com/wa/s_wa.html>!

Cheers,
Craig