Letβs have a combination geology and history lesson today! While I always refer to ancient Egyptian history and hieroglyphs πΉππͺ as my βFirst Love,β my second love is petrology! Most people think geology is solely the study of rocks πππππ¦, however, geology is actually an umbrella term that covers any field that studies the surface and interior of the Earth πΎπΎ! Petrology is solely the study of rocks πππππ¦, and within that field, sedimentary rocks are my absolute favorite type of rock to study!
Even in the pre-dynastic period, ancient Egyptian artisans mastered the art of taking very hard rocks πππππ¦ 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 ππππ. Sedimentary rocks are rocks that formed from tiny pieces (sediments) of pre-existing rocks πππππ¦ and are classified based off the size of the fragments in the rocks πππππ¦. Breccia is defined by the fact that is has fragments over two π» millimeters in diameter, those fragments are angular, and they are suspended in a matrix (natural cement formed by the precipitation of minerals).
Brecciaβs βsister rockβ (as I like to call it) is called conglomerate, which is also found in Egypt ππ ππ! While the rocks πππππ¦ are similar (fragments over two π» 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 before they formed into the conglomerate! The angular fragments signify that the rock ππππ formed quickly after the sediments were deposited!Β
I included a picture ππ ±π 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 βclastsβ). This conglomerate is one of my favorites because it has a βHidden Mickeyβ in it!
This is my personal photograph and original text. DO NOT repost without permission.