Thursday, October 27, 2011

Patterned Quartzite (?) and Petrified Wood, Olympic Peninsula
I set out this morning to look for a source of variolites, the polka-dotted rock I have posted about in the past, and which probably originates in the basalts of the Crescent Formation on the Olympic Peninsula. I tracked down a couple possible source areas - and found no evidence of variolites. In fact, I didn't find a single one, which is unusual - I have found them in a variety of locations along the Olympic coast. This would suggest that the source is somewhere further west than where I was looking today.  So another expedition is clearly required...

However, I did get some time to poke around the coast near Sequim, where I found - among many other things - these two beach cobbles: a stained quartzite (or Jasper?) and a handsome piece of petrified wood. Not bad for a quick beach walk.

Wednesday, October 26, 2011

Missed Opportunity

Owyhee Picture Jasper
I had big plans to head back to the Owyhee country in eastern Oregon this fall to search for more jasper. I had been there in the spring, but high water made access to some of the best collecting sites too difficult, so I promised myself to make an autumn trip.  Well, the rains have started, and autumn has arrived faster than I expected - and my schedule is now too full to allow a minimum three-day trip to the desert. I guess it will have to wait until next year.

These three fragments, polished chips from a piece I collected last spring, will remind me of what I'm missing: one of the greatest collecting locations in the Northwest.

Sunday, October 23, 2011

What the Glacier Dragged In

Unknown Rock, Puget Sound beach
By now you will understand that patrolling the beaches of Puget Sound for unusual stones is one of my favorite spare-time activities. This rock helps explain why. I spent an all-too-short half hour on the beach recently, not finding anything special when this one caught my eye, full of stripes and marbling.  Agate, maybe?  Or something softer like travertine or diatomaceous earth?  I need to test the hardness.

Whatever it is, it is unlike anything I have ever found on the local beaches. Who knows where it's from? My hope, in fact, is that someone somewhere seeing these posted pictures will recognize the rocks from their part of the Northwest. It would be fun to know where the glaciers found them...

Brazilian Gravel Revealed

Unknown Jasper, Amazonian Gravels
As I mentioned in my previous post, I found some extraordinary rocks in the gravels used to line trails at a field camp in the Brazilian Amazon. I have now had a chance to tumble them for a week or so and reveal their color and structure.  As I suspected, they are stunning, full of stained veining like some of the best US picture-jaspers.

The raw pebbles were clearly river rocks - they had the characteristic rounding and light polishing that rocks get from natural tumbling - but no one seemed to know where the gravel was sourced.  A pity, since it is clearly a rich area for fine quality stone. More research is needed...

In the meantime, I have 20-30 very unusual additions to my collection.

POSTSCRIPT : After posting the above I sent an email to a contact in Brazil, hoping to get some details about the source for this miraculous gravel. To my surprise, I already heard back - this gravel is commercially available everywhere in Brazil.  Interesting - and surprising - but sadly, that fact alone doesn't get me any close to finding a source for the original stone!

Wednesday, October 19, 2011

Back from Brazil


Just back from a month in Brazil where, among other things, I was photographing rare giant armadillos (see here ) in the Pantanal. But, as always, I kept my head down, with an eye for interesting rocks - especially since Brazil is one of the most mineral-rich countries on the planet.

Well, not where I was. In fact, most places I visited (Amazon, Pantanal) are flat sedimentary basins with little or no bedrock visible - and frankly not even many rocks. Mud mud and sand, mostly. In fact, the best looking rocks I found were some jasper/chert (not sure which) mixed in with gravels used to line pathways in the Amazon!  I have no idea where the gravels came from - no one seemed to know - but some of them exhibited some striking color and pattern.

While I wait to see what the tumbler reveals, I thought I'd show this pebble I found on a Puget Sound beach a few months ago, a handsome, multi-colored rock of unknown provenance and composition. This is the joy, and the frustration of Puget Sound rockhounding: you find a rock like this, and then never see another. It could be from anywhere...

Meanwhile, stay tuned for shots of the Brazilian gravel. If I'm not mistaken, there could be some real winners from that pathway.