A Polished Gem

I was photographing birds along the shore this morning (see below) but out of the corner of my eye noticed a shiny, rounded pebble with an unusual pattern. I pulled it out of the sand, and rinsed it off. What was immediately obvious was that it was heavy, hard and already very smooth - as if it had already been through a tumbler (which, I suppose you could say, it had).  I will polish it further but hopefully this striking pattern is not just on the surface and will survive the experience.

Speaking of surviving the experience : here's a gull trying to swallow a starfish on the beach below my house this morning. Amazingly, he finally got it down - but he didn't look altogether happy with the decision.

Under the Sand

Sometimes a rock will catch my eye with only a tiny spot visible - that was the case with this handsome stone that was mostly buried under the sand. No idea what it is, with its smooth swirls of red and green, but it was definitely worth digging up and tossing in the bag.  It'll be a month or more before the thing gets a polish.

Treasures of the Conveyor Belt

I have posted many times about the diversity of rock types found along Puget Sound beaches - but I thought this picture tells the story pretty well. These are all stones found within a mile or so of my house and include jasper, agate and petrified wood (inc. the black thing in back) This is pretty typical, though it takes time to find this stuff among the millions of cobbles that line our shores. Still, I would argue that the rock diversity here is as high as any location in the world, largely because of the glaciers that carried stone from locations all over the NW region and kindly dropped them at our doorstep...

(Full disclosure: though found on the local beaches, these puppies have been tumbled and polished at home..)

Finding Jade...?

For some time, I have wondered how to identify jade in the field, especially because the literature suggests it comes in many colors and forms. There is plenty of jade in the Pacific Northwest, so there are almost certainly pieces of it on the Puget Sound beaches I normally patrol.  I found this one a few days ago, and the brilliant color jumped out at me, even in the drizzling rain.  It has the translucence associated with jade, and does not scratch with a steel knife - but how do you know?  More importantly, does it matter?  This will eventually polish into a handsome specimen, jade or not. Still, it would be nice to know.  Any suggestions?

Half and Half

To me, every rock tells a story, and I find this one particularly interesting. It is clearly a piece of what geologists call a "contact," a point where two different rock types abut one another. This can be two layers of sedimentary rock, reflecting a change in the depositional environment (e.g. a layer of mud, followed by a layer of silt) or...

(NOTE: if these were sedimentary layers, they would have been laid down horizontally, not vertically as displayed..)

...or they could represent a molten rock intruding into a crack in an existing rock. (in which the orientation could be in any direction) For example, the black rock may be part of a basalt dike that intruded into whatever the gray-green stuff is.

Or maybe there is something else going on. But whatever the story, it was a striking find on the beach this morning...

Ancient Mystery : Fossil Whale Bone?

I found this fist-sized rock along the shoreline yesterday, and immediately noticed some unusual things about it.  It is very heavy, and filled with linear vesicles - and reminded me of bone, especially whale bone. I don't know if that's what it is - fossil whale bone - but it certainly seems possible. I am going to do some tests, and maybe have someone look at it who might know more than me (which is almost everyone).  Stay tuned.

Follow-up  4/10/12 :  I took the sample to the Paleo team at the Burke Museum today to see if they had any reaction to it. They did, and it pretty much coincided with mine, e.g. "it might be bone....or it might not."  Hardly the conclusive verdict I was hoping for. But yes, it is pretty weathered, pretty small, and does not have any obvious structures that would help identify it.

MAY 2013 UPDATE: I finally got around to cutting  this puppy open and you know what?  It was nothing - some sort of mudstone devoid of any interesting pattern or structure...

"Treasure" Transformed

One of my favorite rocks from the past month was a striking red stone I picked up on a beach near Port Townsend.  I liked it so much, in fact, I posted it on this blog on March 12 (see below), a handsome "jasper" with a graceful white stripe running through it.

Well, after a week in the tumbler, the rock was transformed: the red is gone, and the white squiggle virtually erased. Without doing serious tests, I'm guessing this is not jasper after all, but something much softer - and that the stripe did not run through it, but was just a shallow surface feature. Whatever the explanation, I am both disappointed...and curious. What is this thing? Rarely have I had a stone be so completely altered by relatively slight polishing. Still handsome, but nothing like it was...