You may think of granite as little more than a fancy material for making kitchen countertops out of, and that’s… not wrong, exactly. But it’s not the whole story. Granite is born in the Earth’s molten mantle, and turns up just about everywhere on the planet. It’s hard and durable, so good for building; it can be shined and polished into works of art; it’s even, technically, radioactive.
“Over 40 percent of dimension stone quarried is granite. Crushed granite is used as a durable construction material in asphalt and concrete used in highway and infrastructure projects,” notes the Minerals Education Coalition.
“It is widely used for architectural facades, construction materials, ornamental stone and monuments,” they write. “Because it can be smoothed to a very high polish, granite has found extensive use in memorials, headstones, monuments, carved decorations on buildings, statues and the like.”
Ancient granite
Thanks to this incredible versatility and strength, granite has been one of humanity’s best friends in terms of construction throughout the years. And we really mean years: drilled and worked granite survives from as long ago as the third millennium BCE, with buildings constructed from the unworked stone dating from even earlier than that.
If you’ve been to London or New York, you may have seen some of the most famous examples of this ancient, ancient granite: Cleopatra’s Needles, originally created in the 15th century BCE before eventually being gifted to the two cities in the 1800s, are both sculpted from granite from the quarries of Aswan – now recognized archeological sites due to their historical importance.
Traditionally, this has provoked some disbelief. How could the creators of, say, the sarcophagus of Prince Akhet-Hotep have been technologically advanced enough to drill a rock roughly as hard as steel, some seven centuries before the invention of actual steel?
“Today, quarrymen cut and carve granite using saws with diamond-edged blades and steel chisels. But ancient Egyptian quarrymen and stonemasons didn’t have these modern tools,” explained PBS NOVA way back in 2000. “How, then, did they quarry and cut such clean lines in their obelisks and other monumental statuary?”
Luckily, the ancient stonemasons left us one pretty big clue as to their techniques – and when we say “big”, we mean about 42 meters (137 feet) long and nearly 1100 tonnes (1,200 tons) in weight.
It’s called the Unfinished Obelisk, and that’s for two reasons: it’s an obelisk, and it’s unfinished. Had it ever been completed, though, it would have easily been the largest such erection in the ancient world; even left as it is, horizontal in the ground and still attached to its parent rock, it’s one of the largest monoliths in the world, and the largest known of Ancient Egypt.
“Archeologists know that the ancient Egyptians had the skills to forge bronze and copper tools,” noted PBS – but experiments have proven that this level of tech simply wouldn’t be good enough to carve granite. “We’re losing a lot of metal and very little stone is falling off,” observed stonemason Roger Hopkins upon trying to carve the stone with a copper chisel.
The solution? An ingenious use of a resource Egypt has always had in abundance: sand. “We’re going to put sand inside the groove and we’re going to put the saw on top of the sand,” experimental archeologist Denys Stocks explained. “Then we’re going to let the sand do the cutting.”
That sand is polydispersive – that is, made up of grains of many different sizes – and generally speaking at least 40 percent quartz, making it around as hard as granite itself. “The weight of the copper saw rubs the sand crystals […] against the stone. A groove soon appears in the granite,” noted PBS. “It’s clear that this technique works well and could have been used by the ancient Egyptians.”
From Egypt to Rome
The Romans conquered Egypt in 30 BCE and fell in love with the ancient culture they had found there. Along with Egyptian art, mythologies, and ideas, Rome exported more practical things from their new African province: grain, glass, papyrus – and granite.
“Granite was highly valued by the Romans, who, after the establishment of the Empire, extensively exploited it for monolithic columns,” noted Michael J Waters, Assistant Professor of Art History and Archaeology at Columbia University, in a 2016 paper on Roman architecture.
“The predominant use of large granite columns in Rome, where they were erected by the thousands and adorned some of city’s most spectacular buildings, including the Pantheon, the Forum of Trajan and the Baths of Caracalla and of Diocletian, made them a hallmark of the imperial capital,” he wrote.
But what happened to these multitudinous columns? Well, the thing about history is that there’s only so much of it you can fit in one place. So, Waters explained, “as the Roman marble industry declined in the third century CE, the quarrying of hard stones largely ceased. Consequently, builders in Rome from late Antiquity onward came to reuse ancient granite columns for the construction of new buildings, a practice generally known […] as spoliation.”
In other words, if you ever find yourself admiring one of Rome’s ancient buildings, look a little closer. Chances are, you’re seeing something even older than you realize.
Wonders of the world
Without granite, the planet would be a much less interesting place. Some of the most iconic buildings and constructions in the world owe their existence to the rock: Europe’s castles and churches – including France’s Mont-Saint-Michel, Lisbon’s Évora Cathedral, or Spain’s Santiago de Compostela Arch cathedral Basilica – are built from granite; so too are classic postcard-fodder like Tower Bridge and (parts of) the Great Wall of China.
Mont Saint Michel.
Image Credit: alexseb/Shutterstock.com
In Scotland, an entire city sparkles with the rock: Aberdeen, on the Northeastern coast of the country, owes so much of its infrastructure to granite that it’s literally nicknamed “the Granite City.”
The Brihadisvara Temple, in Southern India, is granite, and truly remarkable in its scope and construction. It was built at the turn of the 11th century and is still one of the tallest in the region. Not for nothing is it called the “Big Temple” by locals: it’s 16 stories high and rises more than 60 meters (197 feet) into the sky.
It was with the Industrial Revolution, though, that the use of granite – along with everything else, let’s be real – took off. With the development of new, heavy-duty transportation options like steamships and trains, as well as modernized techniques for working the material, granite grew from a nice local amenity into the bedrock of Empires.
“Granite has been used for buildings and monuments in Devon and Cornwall from prehistoric times,” wrote Ewan Hyslop and Graham Lott, petrologists and building stone specialists with the British Geological Survey, in a 2007 article for The Building Conservation Directory.
But “the introduction of steam ships stimulated the Cornish granite industry from about 1840, with large quantities used to build docks throughout southern England,” they explained, “and from this time these granites were used extensively in London for numerous monuments, buildings and many of the 19th century commercial dock schemes and bridges. Examples include Nelson’s Column (Foggintor granite) and […] construction of the Thames Embankment.”
But can granite stay as important as it once was? Well, probably, yeah – the worldwide market shows no sign of slowing down. Even with concrete wildly outpacing granite as a building material, and bronze more popular for sculpture, granite is just so darn useful to us that it’s unlikely to be going anywhere soon.
Source Link: Granite: Ancient Wonders, Middle Ages, To Modern Marvels
