Bluestone is the name given to several stones: (1) a feldspathic sandstone in the U. S. , (2) a form of dolerite which appears blue when wet or freshly broken in Britain, and (3) a basalt or olivene basalt in Australia. Diabase (ˈdaɪəbeɪs or Dolerite is a Mafic, Holocrystalline, Igneous rock equivalent to Volcanic Basalt or plutonic

In the United Kingdom

British bluestone is a dolerite, and is currently used to make jewelry or knick-knacks.

Bluestone is an evenly-bedded product which tends to exhibit natural horizontal clefts allowing it to be removed in large flat sections suitable for flagstone, curbing, and the like. Where the clefts are less well defined, the stone is removed in blocks which are then taken to processors for cutting and refining.

The refining process for bluestone slabs is called spalling. This process incorporates water and heat to reveal the natural layers of the stone as it was deposited originally. The cutting orientation must be almost exactly along the horizontal layers. The cut slab surface is soaked with water and heated rapidly with a wide nozzle propane torch, breaking off chips of stone along their fault lines.

Stonehenge in 2005

The bluestones at Stonehenge were placed there during the third phase of construction at Stonehenge around 2600 BC. Stonehenge is a Prehistoric Monument located in the English county of Wiltshire, about west of Amesbury and north of Salisbury The 26th century BC is a Century which lasted from the year 2600 BC to 2501 BC It is assumed that there were about 80 of them originally, but this has never been proven. The stones weigh about 4 tons each. They are believed to have been brought from the Preseli Hills, about 250 miles away in Wales, either through glaciation (erratic theory) or through humans organizing their transportation. Sacred and historic sites Sacred and historic sites of the Preseli Mountains includeBeddyrafanc 51|56|48|N|4|46|25|W|regionGB-PEM_typemountain|display=title}}[[CategoryMountains If a glacier transported the stones, then it must have been the Irish Sea Glacier. It is known that during the Ice Age, probably on more than one occasion a huge Glacier referred to as "The Irish Sea Glacier " flowed southwards from Recently the archaeological find of the Boscombe Bowmen has been cited in support of the latter theory, but there is absolutely nothing, in the opinion of some geologists, to connect the finds with Wales in preference to any other European area of Palaeozoic rocks. The Boscombe Bowmen is the name given by Archaeologists to a group of early Bronze Age individuals found in a shared burial at Boscombe Down near Stonehenge Preseli Bluestone dolerite axe heads have been found around the Preseli Hills as well, indicating that there was a population who knew how to work with the stones (see N P Figgis Prehistoric Preseli). There is also a legend of Merlin having miraculously transported the stones himself. The Multi-Element Radio Linked Interferometer Network ( MERLIN) is an Interferometer array of Radio telescopes spread across England and the

The term 'Preseli Bluestone' is quarryman's name for a whole variety of rock types and strictly is not a petrographic name. At Stonehenge, there are two types of dolerite - spotted and unspotted. The dolerite of the Preselis are plagioclase feldspar. Feldspar is the name of a group of rock-forming Minerals which make up as much as 60% of the Earth 's crust. There is no evidence in Pembrokeshire that spotted dolerite (or any dolerite, for that matter) was used preferentially either for the building of monuments or burial chambers (cromlechs), or for the manufacture of axes. The bluestones may not even have been used preferentially at Stonehenge, and around half of the original stones used in the "bluestone setting" were probably sarsen stones which were later used as lintels. Sarsen stones are stone blocks found in quantity on Salisbury Plain, the Marlborough Downs, in Kent, and in smaller quantities in Berkshire,

In the United States

American bluestone is a feldspathic sandstone, which is produced by about 150 mostly small quarries in adjacent areas of Pennsylvania and New York. Sandstone is a Sedimentary rock composed mainly of Sand -size Mineral or rock grains. The Pennsylvania Bluestone Association has 105 members, the vast majority of them quarriers. Pennsylvania Bluestone is a layered Sandstone found only in the northeastern tier of Pennsylvania, parts of northern New Jersey and the southern tier of

Bluestone from Pennsylvania and New York is commercially known as bluestone or Pennsylvania Bluestone. The Commonwealth of Pennsylvania ( often colloquially referred to as PA (its abbreviation by natives and Northeasterners is a state located in the Northeastern New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous These are a group of sandstones defined as feldspathic greywacke. Feldspar is the name of a group of rock-forming Minerals which make up as much as 60% of the Earth 's crust. Greywacke ( German grauwacke, signifying a grey earthy rock is a variety of Sandstone generally characterized by its hardness dark color and poorly-sorted The sand-sized grains from which bluestone is constituted were deposited in the "Catskill Delta" during the Middle to Upper Devonian Period of the Paleozoic Era, approximately 370 to 345 million years ago. The Devonian is a geologic period and system of the Paleozoic era spanning from to  million years ago. The Paleozoic or Palaeozoic Era (from the Greek palaio (παλαιο "old" and zoe (ζωη "life" meaning "ancient life" If the initial deposit was made under slow moving water the ripples of the water action on the sand or mud will be revealed. This deposition process may be seen today at any ocean beach in shallow water or in a stream bed where conditions allow it to be observed. The term "bluestone" is derived from a deep-blue-colored sandstone first found in Ulster County, New York. Ulster County is a County located in the state of New York, USA. New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous

The Catskill Delta was created from run off from the Acadian Mountains ("Ancestral Appalachians") which covered the area where New York City now exists. This Delta ran in a narrow band from southwest to northeast and today provides the base material for the high-quality bluestone which is quarried from the Catskill Mountains (and Northeast Pennsylvania). The Catskill Mountains (also known as simply the Catskills) a natural area in New York State northwest of New York City and southwest of Albany

As the product became more popular as an architectural and building stone and demand grew, quarrying for it spread throughout south central New York and northeast Pennsylvania. It is a unique commodity of particular value to the economy of Susquehanna County, Pennsylvania. Susquehanna County is a County located in the US state of Pennsylvania. The Commonwealth of Pennsylvania ( often colloquially referred to as PA (its abbreviation by natives and Northeasterners is a state located in the Northeastern

This bluestone is made into products as follows: The bluestone is separated from the rock (quarry face) in the quarry by parallel cuts with saws with diamond-tipped blades into large rectangular blocks. A quarry is a type of open-pit mine from which rock or Minerals are extracted In Mineralogy, diamond is the allotrope of carbon where the carbon atoms are arranged in Sometimes the stone is lightly blasted to encourage splitting along parallel planes of weakness, delineating the top and bottom of the block. The final products are often made in the quarry, but sometimes massive blocks are trucked to "saw shops" to be finished there, by sawing, by "snapping" or breaking the stone with a guillotine along a line of pressure points, or by splitting along planes of weakness.

The largest volume product is ordinary irregularly-edged flagstone, followed by ashlar. Flagstone belongs to a group of products that require no (or very little) sawing, such as rubble masonry and landscape stone. Flagstone is a type of flat stone, usually used for paving slabs but also for making Fences or Roofing. Two other product groups are classified as Architectural Stone, one group that requires some sawing or "snapping" such as paving stone, wall stone, ashlar, bridge stone, and curbing, and the other group that requires sawing on all surfaces, such as countertops, stair treads, lintels, thresholds, ashlar, sidewalks, and residential walls (veneer). The ashlar can be sawn on all six surfaces, or "snapped" on one or more surfaces with the remaining surfaces sawn.

External links

• http://www.stoneofpa.com

In Australia

Australian bluestone is a basalt or olivene basalt, and is quarried by one full-time producer and one part-time producer.

HM Prison Pentridge was one of the many buildings constructed of local bluestone in Melbourne in the 19th century

In Victoria, Australia, bluestone was one of the favoured building materials of the 1850s during the Victorian Gold Rush. The Victorian Gold rush was a period in the history of Victoria, Australia approximately between 1851 and the late 1860s

In Melbourne it was extracted from a quarry in the Clifton Hill area and used extensively in the 19th century. Melbourne ( is the second most populous city in Australia, with a Metropolitan area population of approximately 3 Clifton Hill is a Suburb of Melbourne, Victoria, Australia. It is in the Local Government Area of the City of Yarra The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar Because the material was difficult to carve, it was predominantly used for warehouses and the foundations of public buildings. Significant bluestone buildings include the Melbourne Gaol, HM Prison Pentridge, St Patrick's Cathedral, Victoria Barracks, Melbourne Grammar School, Deaf Children Australia and Victorian College for the Deaf, Royal Victorian College for the Blind, the Goldsborough Mort warehouses (Bourke Street) and Timeball Tower. The Old Melbourne Gaol is a Museum and former Prison located in Russell Street, Melbourne, Victoria, Australia HM Prison Pentridge was an Australian prison built in 1850 with the first prisoners arriving in 1851 and located in Coburg, Victoria. Patrick's Cathedral is the cathedral church of the Roman Catholic Archdiocese of Melbourne in Victoria Australia, and seat of its archbishop currently Located on St Kilda Road in Melbourne, Australia, Victoria Barracks Melbourne is of architectural and historical significance as one of the most impressive Melbourne Grammar School is an independent, Anglican, day and Boarding school predominantly for boys located in South Yarra Deaf Children Australia is a charity that supports young Deaf and Hearing impaired people in Australia. The Victorian College for the Deaf (VCD located on St Kilda Road in Melbourne Australia, is Victoria's oldest deaf school opening in 1860 Bourke Street Mall Redevjpg|thumb|200px|Bourke Street Mall during redevelopment]] Bourke Street is a major street in the central business district (CBD of Melbourne The Williamstown Lighthouse is situated at Gellibrand Point ( in the Melbourne suburb of Williamstown. It was also used extensively for cobblestone roads, many which still exist in some of Melbourne's smaller lanes as well as walls, bridges, curbs and gutters in many of the inner suburbs. A list of Lanes in Hoddle Grid. ACDC Lane Albert Coates Lane (Queen Victoria Village Some examples of structures that use the material include Princes Bridge and Federation Wharf and Hawthorn Bridge. Hawthorn Bridge crosses the Yarra River five kilometers east of Melbourne connecting Bridge Road and Burwood Road. Because of its distinctive qualities, post-modern Melbourne buildings have also made use of nostalgic bluestone, including the Southgate complex and promenade in Southbank, Victoria and apartments such as the Melburnian. Southbank is an Inner city suburb of Melbourne, Australia in the state of Victoria.

It was also sourced in many other regions of the Victorian volcanic plains and used in towns and cities of central and western regions including Ballarat, Geelong, Port Fairy and Portland. Ballarat (formerly spelt "Ballaarat" is a city in Victoria, Australia, and one of the country's largest inland cities MCite/Citephp.--> Geelong (dʒəˈlɔŋ is the second largest city in the state Port Fairy is a coastal town in western Victoria, Australia. It is located on the Princes Highway in the Shire of Moyne west of Warrnambool The city of Portland is the oldest European settlement in what is now the state of Victoria, Australia.

References

External links

• Examination of the conflicting theories relating to the Stonehenge bluestones
• Enigma of the Stonehenge Bluestones and the Preseli Hills
• Wessex Archaeology's Bluestone information
• How American bluestone is quarried
• Pennsylvanian bluestone
• AGI Trade Solutions in naturalstone
• Article on Cultured Bluestone