Someone --

Left this bit of "wild coal" in the form of a cobble of Jet. This occurs within the Cenzoic sediments of the Mesohellenic Trough west (and upstream) of the Aliakmon Valley, but I never thought someone would find a bit in the Aliakmon itself.

Width about 5 cm.

And the photo doesn't do justice to the shininess of this surface. 

Honeycomb rock

This is a Palezoic limestone reduced to paper-thin cells by seaside gastropods of some sort.

We craced some of these open at Glyfa, and found some to contain to guilty animals -- apparently they bore through the rock at an early stage of their development, then grow larger INSIDE the rock. They must have some acidic saliva to disolve limestone so efficiently.

I've never seen this in the fossil record, but I assume they must be there?

Each "honeycomb cell" at the top of the photo is about 0.5 cm in diameter. 

Orliakas Limestone --

White, lovely, and the swaths crossing the image are imprints of fossil rudistids (80 million years or so).

Image about 5 cm wide. 

On the subject of fossils --

A shell imprint on a Cenzoic limestone deposited on top all the mess in the Aliakmon River Valley. Found by Giovanna, Frederica, and Maria.

Shell imprint about 2 cm across 

In a Brach-ish state of mind--

An old round cobble from upstate New York holds Silurian brachipiods when split in two.

Someone stole the other half.

Large brach about 1 cm. 

Guest Star!

Peridotite from the Urals!

Field of view about 4 cm across.

Sigh. I can lose myself looking into rocks like this for hours. 

Green and Blue --

Malachite and Azurite, to you.

On a fracture surface of diabase near some hydrothermal copper minerals that left the trace of their alteration behind.

From Monahiti, Greece.

Width of photo ~5 cm. 

The Sole of the Ophiolite .

Garnet Amphibolite, kids.

I found this in one of your scrap piles by the school. Shiny black amphibole, deformed altered feldspars (probably rodingtite as of now), and those lovely red garnets. The garnets are about 2-3 mm in diameter. 

Hold a magnet up to the screen--

--and see if it sticks.

Magnetite, as black grains and black layer, formed here as a reaction between an ultramafic rock (lower) and felsic (upper) intrusion.

From the Othris Ophiolite. The white felsic layer is about a cm thick. 

Rhyolite --

--from the Othris Ophiolite, Greece, though I have no idea what it's doing there.

The pink grains, each several mm in size, are orthoclase. The greenish-grey groundmass is tuffaceous stuff. 

Very deep rock --

For a sedimentary rock, anyway. Red chert with white secondary chalcedony from the Aliakmon Valley.

Red chert like this is initially a sedimentary muck collecting on the sea floor at depths greater than 4000m, far deeper than calcite can survive.

Width of view about 6 cm 

Don't Spilite

A volcanic rock from oceanic pillow lava. Once full of bubbles now (in this sample) filled with calcite and zeolite. The layering seems to be more (greenish) or less (reddish black) proportions of hyaloclasitic material altering to clay with less hyaloclastic rich lava.

From the Pindos, Greece. Width of sample is about 1.6 cm. 

If it's green --

--it's olivine.
Usually this doesn't work, but the olivine in this very fresh dunite from Voidolakkos (Vourinos) is indeed green. The black accessory minerals are chromite, aka, chrome spinel.

Width of view is about 4 cm. 

A Wild and Wacke Stone

This is a wondrous whacky wackstone.
The round (1 cm diameter) white limestone fragment appears to be a fossil. The largish black fragment in the lower right is basalt. All the other liths and matrix fragments appear to be "somethings in between."

From the Aliakmon River Valley -- it followed me home. I had to keep it.