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Egyptian Artifacts

Sedimentary Rocks in Ancient Egypt

Let’s have a combination geology and history lesson today! While I always refer to ancient Egyptian history and hieroglyphs π“ŠΉπ“Œƒπ“ͺ as my β€œFirst Love,” my second love is petrology! Most people think geology is solely the study of rocks π“‡‹π“ˆ–π“‚‹π“ˆ™π“¦, however, geology is actually an umbrella term that covers any field that studies the surface and interior of the Earth 𓇾𓇾! Petrology is solely the study of rocks π“‡‹π“ˆ–π“‚‹π“ˆ™π“¦, and within that field, sedimentary rocks are my absolute favorite type of rock to study!

Sedimentary Rocks
A stone vessel from the pre-dynastic period made from the sedimentary rock breccia (Brooklyn Museum)

Even in the pre-dynastic period, ancient Egyptian artisans mastered the art of taking very hard rocks π“‡‹π“ˆ–π“‚‹π“ˆ™π“¦ and turning them into something beautiful π“„€ – as is the case with this Breccia jar dated to c. 3500-3100 B.C.E. Breccia was mainly used to make these stone jars, and rarely is it seen in other statuary. 

Breccia is classified as a clastic sedimentary rock π“‡‹π“ˆ–π“‚‹π“ˆ™. Sedimentary rocks are rocks that formed from tiny pieces (sediments) of pre-existing rocks π“‡‹π“ˆ–π“‚‹π“ˆ™π“¦ and are classified based off the size of the fragments in the rocks π“‡‹π“ˆ–π“‚‹π“ˆ™π“¦. Breccia is defined by the fact that is has fragments over two 𓏻 millimeters in diameter, those fragments are angular, and they are suspended in a matrix (natural cement formed by the precipitation of minerals). 

Breccia’s β€œsister rock” (as I like to call it) is called conglomerate, which is also found in Egypt π“†Žπ“…“π“π“Š–! While the rocks π“‡‹π“ˆ–π“‚‹π“ˆ™π“¦ are similar (fragments over two 𓏻 millimeters in diameter, fragments in a matrix), their main difference is that conglomerate has rounded fragments! Why do we care about that difference? If the fragments are round, it means they traveled a far distance in water π“ˆ— before they formed into the conglomerate! The angular fragments signify that the rock π“‡‹π“ˆ–π“‚‹π“ˆ™ formed quickly after the sediments were deposited!Β 

Sedimentary Rocks
A piece of the rock conglomerate, which was found by me on the North Shore of Long Island. This is from my personal rock collection.

I included a picture 𓏏𓅱𓏏 of a conglomerate from my personal collection (I also found this rock myself) so you can see the difference in the shape of the fragments (scientifically referred to as β€œclasts”).  This conglomerate is one of my favorites because it has a β€œHidden Mickey” in it!

This is my personal photograph and original text. DO NOT repost without permission.