Week 10 Flashcards
Why is graphite used as a writing material?
Graphite is very soft (hardness of 1) and leaves a black streak on harder surfaces like paper
What were the first paints likely mixtures of?
pigment, clays, animal fats and “filler” minerals.
Paint consists of
pigment and binder
Examples of common natural pigment
- Vermillion (cinnabar)
- Terre Verte (glauconite clay)
- Ultramarine (lapis lazuli)
Artificial inorganic pigments
Coloured pigments that are produced rather than found. The ultimate sources of metals in these pigments are minerals
Organic pigments
include both natural forms and manufactured synthetic forms
Why did the Egyptians build pyramids?
Pyramids may have symbolized the sun’s rays, helped the king’s soul ascend to the gods, or aligned with Orion’s belt for spiritual or astronomical reasons.
The largest Egyptian Pyramid
Khufu Pyramid
Pyramid interiors
Pyramids contain chambers and tunnels—not solid throughout.
Chambers held the pharaoh, queen, and their belongings. Some internal features remain a mystery.
What is special about the limestone used to build the pyramids at Giza?
It’s made of nummulites: coin-sized shells of ancient foraminifera from the early Cenozoic.
Modern foraminifera still exist but are much smaller.
The Great Sphinx
a human-lion hybrid, possibly representing the Sun God.
Its true purpose is unknown
What’s another theory about the origin of the Sphinx?
It may have started as a failed quarry.
To avoid leaving an eyesore at Giza, builders reshaped it into the Sphinx… a creative way to turn a blemish into art.
What are the Moai statues of Easter Island made from?
Moai were carved from volcanic ash on an island formed by basaltic lava and pyroclastic debris.
Who were the islanders?
Polynesian people from the west
What do the Moai statues represent?
Moai were built as guardians by the ruling class (“long ears”) and represent buried ancestors.
Adding coral and obsidian eyes symbolized a king’s rebirth in the statue.
Why were the Moai statues carved without legs?
to prevent them from “walking around” … a mythical idea tied to their spiritual power.
Do the Easter “heads” have bodies?
Yes - discovered during excavation in 2010
How were the Moai statues moved?
recent experiments suggest Moai were “walked” by rocking them back and forth, as described in islander stories.
What is the first stage of Stonehenge’s construction?
Around 3000 BCE, the first version of Stonehenge featured a ditch, banks, and 56 small pits called the Aubrey Holes, likely used for wooden posts.
What happened during the second stage of Stonehenge’s construction?
“bluestones” made of diabase (a fine-grained version of gabbro) were placed at the center.
The rock contains white spots of plagioclase feldspar, known as dolerite in the UK.
What happened during the third stage of Stonehenge’s construction?
“sarsen stones” (hard sandstone) were added:
- One set formed an inner “horseshoe.”
- A larger ring (Sarsen Circle) surrounded it.
What is the “Slaughter Stone” at Stonehenge?
lies between the central monument and the Heel Stone.
Its name comes from the mistaken belief that it was used for sacrifices, with red water in its hollows thought to be blood.
Was Stonehenge an ancient observatory?
Yes, it’s believed the stones marked the positions of the moon and sun.
Honeycombing
the drilling of holes to certain depths and removing intervening rock with hammers and chisels
What is concrete?
a mixture of cement, sand, rock, water and small amounts of additive
What is cement?
a fine grey powder that looks very much like gray flour.
Raw materials: Calcite and Silica + Additives: Alumina and Iron Oxide
Process of making cement
Raw materials are crushed, heated to 900°C, then passed through a rotary kiln at 1500-1600°C to create clinker. It’s cooled, mixed with gypsum, and milled into cement.
