Egyptian Museum
Egyptian Museum in Cairo, Egypt, is home to an extensive collection of ancient Egyptian antiquities. It has 160,000 items, with a representative amount on display, the remainder in storerooms. Built in 1901 by the Italian construction company Garozzo-Zaffarani to a design by the French architect Marcel Dourgnon, the edifice is one of the largest museums in the region. In 2020 the museum is due to be superseded by the new Grand Egyptian Museum at Giza (planned to be open in Q4/2020).
This Earthcache is dedicated to the basic material of ancient Egypt - stone - rocks - granite. The Egyptian Museum features many artifacts that are just carved out of granite. So let's talk about this important building block.
Granite
Granite is a common type igneous rock that is granular and phaneritic in texture. Granites can be predominantly white, pink, or gray in color, depending on their mineralogy. The word "granite" comes from the Latin granum, a grain, in reference to the coarse-grained structure of such a completely crystalline rock. Strictly speaking, granite is an igneous rock with between 20% and 60% quartz by volume, and at least 35% of the total feldspar consisting of alkali feldspar, although commonly the term "granite" is used to refer to a wider range of coarse-grained igneous rocks containing quartz and feldspar.
A microscopic picture of granite
Granite is nearly always massive, hard, and tough. These properties have made granite a widespread construction stone throughout human history. The average density of granite is between 2.65 and 2.75 g/cm3, its compressive strength usually lies above 200 MPa. The melting temperature of dry granite at ambient pressure is 1215–1260 °C; it is strongly reduced in the presence of water, down to 650 °C.
Industry
Granite and related marble industries are considered one of the oldest industries in the world, existing as far back as Ancient Egypt. Major modern exporters of granite include China, India, Italy, Brazil, Canada, Germany, Sweden, Spain and the United States.
Uses
Antiquity
The Red Pyramid of Egypt (c. 26th century BC), named for the light crimson hue of its exposed limestone surfaces, is the third largest of Egyptian pyramids. Menkaure's Pyramid, likely dating to the same era, was constructed of limestone and granite blocks. The Great Pyramid of Giza (c. 2580 BC) contains a huge granite sarcophagus fashioned of "Red Aswan Granite". The mostly ruined Black Pyramid dating from the reign of Amenemhat III once had a polished granite pyramidion or capstone, which is now on display in the main hall of the Egyptian Museum in Cairo. Other uses in Ancient Egypt include columns, door lintels, sills, jambs, and wall and floor veneer. How the Egyptians worked the solid granite is still a matter of debate. Patrick Hunt has postulated that the Egyptians used emery, which has greater hardness on the Mohs scale.
Rajaraja Chola I of the Chola Dynasty in South India built the world's first temple entirely of granite in the 11th century AD in Tanjore, India. The Brihadeeswarar Temple dedicated to Lord Shiva was built in 1010. The massive Gopuram (ornate, upper section of shrine) is believed to have a mass of around 81 tonnes. It was the tallest temple in south India.
Imperial Roman granite was quarried mainly in Egypt, and also in Turkey, and on the islands of Elba and Giglio. Granite became "an integral part of the Roman language of monumental architecture".The quarrying ceased around the third century AD. Beginning in Late Antiquity the granite was reused, which since at least the early 16th century became known as spoliation. Through the process of case-hardening, granite becomes harder with age. The technology required to make tempered steel chisels was largely forgotten during the Middle Ages. As a result, Medieval stoneworkers were forced to use saws or emery to shorten ancient columns or hack them into discs. Giorgio Vasari noted in the 16th century that granite in quarries was "far softer and easier to work than after it has lain exposed" while ancient columns, because of their "hardness and solidity have nothing to fear from fire or sword, and time itself, that drives everything to ruin, not only has not destroyed them but has not even altered their colour."
Modern
Sculpture and memorials
Various granites (cut and polished surfaces). In some areas, granite is used for gravestones and memorials. Granite is a hard stone and requires skill to carve by hand. Until the early 18th century, in the Western world, granite could be carved only by hand tools with generally poor results.
A key breakthrough was the invention of steam-powered cutting and dressing tools by Alexander MacDonald of Aberdeen, inspired by seeing ancient Egyptian granite carvings. In 1832, the first polished tombstone of Aberdeen granite to be erected in an English cemetery was installed at Kensal Green Cemetery. It caused a sensation in the London monumental trade and for some years all polished granite ordered came from MacDonald's. As a result of the work of sculptor William Leslie, and later Sidney Field, granite memorials became a major status symbol in Victorian Britain. The royal sarcophagus at Frogmore was probably the pinnacle of its work, and at 30 tons one of the largest. It was not until the 1880s that rival machinery and works could compete with the MacDonald works.
Modern methods of carving include using computer-controlled rotary bits and sandblasting over a rubber stencil. Leaving the letters, numbers, and emblems exposed on the stone, the blaster can create virtually any kind of artwork or epitaph.
The stone known as "black granite" is usually gabbro, which has a completely different chemical composition.
Buildings
Granite has been extensively used as a dimension stone and as flooring tiles in public and commercial buildings and monuments. Aberdeen in Scotland, which is constructed principally from local granite, is known as "The Granite City". Because of its abundance in New England, granite was commonly used to build foundations for homes there. The Granite Railway, America's first railroad, was built to haul granite from the quarries in Quincy, Massachusetts, to the Neponset River in the 1820s.
To the cache:
At the time of this cache's creation in February 2020, a red granite obelisk tip was installed in the garden of the Cairo Egyptian Museum. In June 2022, this artifact was transferred to the new GEM museum in Giza. Originally, one of the tasks related to this very artifact, when every geocacher had to take a picture in front of it. Here are the quests for this earthcache:
1. What causes the red color of the granite?
2. Where in Egypt is its highest prevalence?
Please send me these answers via profile.
Please attach the following tasks to the log:
3. Write down what artifact (can be from red granite) you liked most at the Egyptian Museum.
4. Find some red granite artifact in the Egyptian museum and take a picture in front of it (if you don't want to, just take a picture of your finger or your nickname written on paper) so that I can identify that you visited the museum.
I invite those who do not send answers to do so. If the geocacher does not do so, his log will be deleted. Thank you. Owner.
Entrance for foreigners in 2020 to the museum (as well as to the garden): 200 LE (subject to change).