The building stones composed of coral-bearing limestone are my favorite.

Corals, I note, are considered as rock-building creatures, since their skeletons make up the limestone itself. Could we consider humans as rock-building creatures? Not with our skeletons, luckily, but we surely could consider our buildings and our garbage dumps as "man-made" rock formations. 

The good stuff in the walls is limestone, not marble, and I'll hazard a guess that it's Cretaceous but haven't looked it up.

There are an abundance of stones full of bivalves, as in this stone... 

First note that these old guys that build the walls did not waste money. The wall here has an internal wall made of conglomeratic stones (possibly derived locally?), and the more showy (and expensive) marble makes up the outer walls. 

What stones make up the fortress of the Acropolis?

The walls of the Acropolis are an amazing record of the geology of Greece. The building stones are a mix of those used in the original construction, some added at various ages to fix things up, a few that one thinks might be the additions of a cheapskate constractor of whatever era, and stones added today to help us visit. 

The Parthenon Marbles Today

Thirty years ago when I first visited the Parthenon, the mica and pyrite glinted silver and gold. Since then, the air pollution has weathered these minerals to lines of grey rust within the marble. Two years ago, I could find fresh pyrite in only a single block exposed on the tourist's trail, but last week, that too was oxidised. There's no way to undo this damage, but consider instead that the marbles of the Parthenon are still evolving to the changing conditions of the world today. Evolution means life. 

Inside the Marble of the Parthenon

The marble of the Parthenon itself is not pure white stone, but a lovely marble with tracings of silvery mica and gold pyrite. This excellent stone was chosen, I believe, simply because it was beautiful. There were plenty of marble quarries to chose from, but the ancients celebrated this stone, and while you can visit its quarry today, sadly the supply of this marble have been exhausted.
I also suspect, that this marble contributed the inspiration for all the cheap plastic tiles in low-cost hotels scattered over the world. 

Pure White Marble

This is what most folk imagine marble to be -- pure white rock, frozen remnant of former sea life. This column, from near the Theater of Dionysos, certainly demonstrates that our ancients had access to an abundance of pure white marble, yet in the photos above and below, you'll see that use of this type is in no way universal. 

The Columns of the Acropolis

The buildings of the Acropolis date to a period of about a thousand years, during which the styles of columns changed --no not just the Doric to Corinthian architectural styles, but the essence of the stones themselves. These, from the early Roman period, are marble with swirling veins of white calcite. 

Journey to the Underworld beneath the Acropolis

The archeological story of the Acropolis goes back several thousand years. The Geological story starts some half billion years ago, and continues today. Some photos of my favorite geological sites on the Acropolis follow in the postings above.

Hope you enjoy them!