marble

Marble is beautiful to look at when used in the form of art…

But a dangerous and a disaster to our environment, health and the downside to having it in our lives...

Beware follow artist, be aware of the price you pay for the beauty in your artwork.

 

Poem by Marlow

 

What is marble?

Marble is a metamorphic limestone.  When limestone is heated and has pressure put on it, its calcite is melted.  Larger crystals are formed and this is marble.  Whatever is mixed in with the limestone decides the final color of the marble.  If limestone is pure, you get a white marble.   If it has hematite or clay in it, you will get a reddish color marble. Most marble is large grained and comes in many colors and patterns.

 

Where is marble extracted?

Marble is mined in mountain areas using quarrying.  It is found in:  Canada, Italy, Germany, and Spain.  In the U.S., the best come from Vermont but there are quarries in Maryland, Tennessee, Massachusetts, and lots of other states.

 

What is it used for?

Marble is used in statues, buildings, tomb stones, fireplace mantles, floor tiles, and countertops. It is soft and is easy to carve or cut into shapes. Marble was used in Ancient Greece to make statues and buildings like the Parthenon.

 

 

How marble is extracted...

The real revolution of the marble extraction techniques took place at the end of the 19th century with the invention of the helical wire and the penetrating pulley. The technique is based on a 4 to 6 millimeters diameter steel wire combined with the abrasive action of silica sand and an abundant amount of water as a lubricant.

 

The helical wire is a continuous loop of tensioned steel that moves at a speed of 5 to 6 meters per second and cut the marble at a rate of 20 centimeters per hour. The use of this new technique almost completely substituted the use of explosives and determined a visible change in the landscape. The mountain begun to be literally cut with precision, creating surreal landscapes made of huge flights of steps and platforms, called "piazzali di cava".

 

"Diamond wire cutting was invented in England in the 1950s, initially by diamond electroplated beads threaded onto a multi-strand steel cable. Over the past 30 years significant development work (by Diamant Boart, among others) refined the concept until it was commercially accepted in Carrara marble quarries in Italy", wrote Shane McCarthy in a remarkable paper about diamond wire cutting (Queensland Roads Technical Journal, March 2011, pp. 29-39).

 

Diamond wire sawing is still in use today in the marble industry, especially in Carrara. "The diamond wire sawing requires drilling initially two perpendicular holes (one horizontal at the base of the bench and a vertical from the top) which meet, according to the block size to cut. Then the cable is rotated by a machine placed on rails. By turning, the cable saws the rock. The machine backs progressively on the rails so as to keep the cable tensioned until the end of cutting. This technique is widely used as it allows for calibrated and easy to rework blocks with sharp edges"

http://mining.about.com/od/Quarrying/a/The-Evolution-Of-Marble-Extraction-Techniques.htm

http://www.stone.poplarheightsfarm.org/marble_production.HTM

 

Quarry effects on local environment

Whilst a quarry is in use the effects on the local environment are more than just the loss of wildlife habitats and the obvious visual impact. A working quarry needs methods of transportation and this means that large amounts of machinery and heavy traffic will be brought into the area, causing an increase in local noise, pollution and erosion.

Sand and gravel extraction may often leave behind large water filled pits. These pits, if managed correctly, may become valuable wildlife habitats for wetland and water creatures.

Sometimes they are also used as leisure lakes for water sports although this may conflict with the needs of wetland wildlife.

 

Stone quarries come in different shapes and sizes. Some, like the gravel pits are relatively easy to reclaim. Many disused quarries, once they have been made safe, are used for leisure areas such as camp sites or motor vehicle racing tracks but the reclamation of others is more difficult. Removal of vast quantities of rock can change the very shape of our environment. Whole hillsides can be destroyed and layers of valuable soil removed.

Since 1981 there has been a time-limit imposed on those who seek to extract from the land. They are not allowed to quarry for an indefinite amount of time. Companies are also required to ‘reinstate’ the land – this can involve years of careful drainage and land management in order to get the area back to a state where it can be used.

Any amount of careful management, however, will not return the land to the way it was before the rock was extracted and the species of flora and fauna that were disturbed and destroyed may never be able to re-establish themselves in that area again.

http://www.ypte.org.uk/environmental/quarrying-and-mineral-extraction/79