Karlshausen and T. De Putter. De Putter, T. Klemm, R. Berlin Heidelberg New York: Springer, Klemm, D. Journal of African Earth Sciences 33 : — James A. Harrell There are no affiliations available. Toledo, Ohio , USA. Much of what remains of ancient Egypt consists of stone. There are building stones for temples, pyramids, and tombs; ornamental stones for vessels, sarcophagi, shrines, stelae, statues, and other sculptures; gemstones for jewelry; and utilitarian stones for tools, weapons, pigments, and other applications.
Still other stones were processed to extract their precious metals. There are three general categories of rocks — sedimentary, igneous, and metamorphic, and these are further subdivided according to their textures and constituent minerals.
Sediments mud, sand and gravel deposited on ocean floors and land surfaces are hardened into sedimentary rocks through a variety of lithification processes, including compaction, cementation, and recrystallization.
Continental sediments are derived from weathered and eroded pre-existing rocks, and are deposited mainly by rivers but also occasionally by wind, glaciers, and other processes. Marine sediments, in contrast, are composed mainly of biogenic material hard skeletal parts of algae, protozoa, and especially invertebrate animals or inorganic precipitates produced by evaporation of seawater, but also sometimes include continental sediments carried by rivers to the seas.
Other sedimentary rocks are the result of secondary mineralization of pre-existing sedimentary rocks. Sedimentary rocks used by the ancient Egyptians include: limestone from biogenic marine sediments ; rock gypsum and rock anhydrite both from evaporative marine sediments ; sandstone, including siliceous quartz-cemented sandstone or quartzite from continental sediments and, in part, shallow nearshore marine sediments ; and travertine and chert both from secondary mineralization of limestone.
Nearly all the ancient quarries for limestone, travertine and chert were located in the hills and cliffs bordering the Nile River valley between Cairo in the north and Isna in the south. Quarries in the Nile valley from Isna southward into northern Sudan supplied the sandstone. A beautiful blue rock anhydrite comes from an unknown source and may have been imported into Egypt.
Igneous rocks form through the crystallization of magma molten rock. Igneous rocks used by the ancient Egyptians include: granite, granodiorite, quartz diorite, diorite, and pyroxenite plutonic intrusives ; andesite and dolerite porphyries as well as other porphyritic rocks volcanic dikes and lava flows ; basalt and obsidian volcanic lava flows ; and tuff and related rocks volcanic pyroclastics. Apart from the famous granite and granodiorite quarried at Aswan on the Nile River, the igneous rocks came from the Faiyum in the Western Desert basalt and especially the mountains of the Eastern Desert all other rocks, excluding obsidian.
Obsidian volcanic glass does not occur in Egypt, and was imported from the eastern Mediterranean and southern Red Sea regions. The metamorphosis occurs in the solid state without melting through secondary mineralization and recrystallization. The resulting rocks are either foliated, with a parallel alignment or planar segregation of their constituent minerals, or non-foliated. Metamorphic rocks used by the ancient Egyptians include: anorthosite gneiss and tonalite gneiss foliated ; and marble, metaconglomerate, metagabbro, metagraywacke, serpentinite, and steatite non-foliated.
The anorthosite gneiss comes from the Nubian Desert west of Lake Nasser, and the other rocks were quarried in the mountains of the Eastern Desert. The other stones employed by the ancient Egyptians are minerals found mostly within the plutonic and metamorphic rocks. These are the gemstones used for jewelry and include: amazonite, a variety of microcline feldspar; emerald, a variety of beryl; garnet; peridot, a variety of olivine; numerous varieties of quartz agate, amethyst, carnelian and other colored chalcedonies, jasper, milky quartz, and rock crystal ; and turquoise.
These minerals were quarried in the Sinai turquoise , St. Lapis lazuli, a gemstone rock rather than a mineral, was also widely used in Egypt but was apparently imported from Afghanistan. Enter the password to open this PDF file:. Cancel OK. File name: -. File size: -. Title: -. Author: -. Subject: -. Keywords: -. Creation Date: -. Modification Date: -. Creator: -.
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