Bristol Diamonds
Encyclopedia
Bristol Diamonds are not actually diamond
s but quartz
crystals found in geodes, geological
rock
formations which occur in dolomitic
conglomerate
found in the Avon Gorge
in Bristol
, England
. Their origin lies in geological processes of the Triassic
period, about 250 to 200 million years ago.
The Bristol Diamonds became popular novelties for visitors to the spa at Hotwells, Bristol, during the eighteenth and nineteenth centuries. Diarist John Evelyn
and travel writer Celia Fiennes
were amongst those who described them. In popular culture they became a synonym for something bright but worthless.
period (about 250 to 200 million years ago) in the Bristol
Avon Gorge
as a result of clays mingling with rock debris scree
which had formed against the Carboniferous limestone
cliffs of the gorge. The geodes containing the Bristol Diamonds are frequently found in this conglomerate, in the areas of Bridge Valley Road, Leigh Woods
, Sea Mills
and St Vincent's Rocks. The geodes were formed from quartz, either megaquartz or fibrous quartz, the diamonds themselves resulting from the dissolution of nodules of anhydrite
leaving a void which allowed the silica crystal
s to grow.
's topographical
survey of Great Britain and Ireland, published in 1586, the diamonds are described:
In 1654, diarist John Evelyn
visited Bristol and, like many other visitors, went hunting for the diamonds, "what was most stupendous to me was the rock of St. Vincent, the precipice whereof is equal to anything of that nature I have seen in the most confragous cataracts of the Alps. Here we went searching for Bristol diamonds and to the Hotwells at its foot." The late seventeenth century English
traveller Celia Fiennes
described them,
The central hall of Goldney Grotto, an ornate feature of the 18th century gardens at Goldney House, Clifton
, contains columns covered with the crystals. The diamonds were often referred to "as examples of worthless but deceptive brilliance." Thomas Carlyle
, in a letter dated 1828, used them in a simile
disparaging the latest work of the poet Thomas Moore
, as being "resplendent with gold-leaf and Bristol diamonds, and inwardly made of mere Potter's-clay."
Bristol Diamonds became popular souvenir
s for visitors to the spa
at Hotwells in the early nineteenth century, and were also used for jewellery, although Benjamin Silliman, a nineteenth century American
traveller, considered them overpriced. They were described by Chilcott, in Chilcott's new guide to Bristol, Clifton and the Hotwells (1826) as sometimes "exceedingly clear and brilliant, and of so hard a nature as to cut glass ... sometimes tinged with yellow, sometimes purple".
Sample Bristol Diamonds were exhibited as part of the geology of Bristol section at London
's The Great Exhibition
, in 1851.
Bristol Diamonds was the title of a popular one act farce
by nineteenth century dramatist John Oxenford
, premièred at St James's Theatre
, London in 1862 and described by the Daily News
as a "capital farce, with a good plot, and most humorous dialogue." Nineteenth century romantic novelist Emma Marshall published Bristol diamonds: or, The Hot wells in the year 1773, the plot of which centred on a brooch made of Bristol Diamonds.
Eighteenth and nineteenth century collection and quarrying in the Avon Gorge have exhausted the once ready supply of Bristol Diamonds, although some are still occasionally discovered. Examples can be seen at the University of Bristol
's Geology Museum and at Bristol City Museum.
Diamond
In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...
s but quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
crystals found in geodes, geological
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
rock
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
formations which occur in dolomitic
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....
conglomerate
Conglomerate (geology)
A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...
found in the Avon Gorge
Avon Gorge
The Avon Gorge is a 1.5-mile long gorge on the River Avon in Bristol, England. The gorge runs south to north through a limestone ridge west of Bristol city centre, and about 3 miles from the mouth of the river at Avonmouth. The gorge forms the boundary between the unitary authorities of...
in Bristol
Bristol
Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...
, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. Their origin lies in geological processes of the Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
period, about 250 to 200 million years ago.
The Bristol Diamonds became popular novelties for visitors to the spa at Hotwells, Bristol, during the eighteenth and nineteenth centuries. Diarist John Evelyn
John Evelyn
John Evelyn was an English writer, gardener and diarist.Evelyn's diaries or Memoirs are largely contemporaneous with those of the other noted diarist of the time, Samuel Pepys, and cast considerable light on the art, culture and politics of the time John Evelyn (31 October 1620 – 27 February...
and travel writer Celia Fiennes
Celia Fiennes
Celia Fiennes was an English traveller. Born in Wiltshire, she was the daughter of an English Civil War Parliamentarian Colonel, who was in turn the second son of the William Fiennes, 1st Viscount Saye and Sele. Celia Fiennes died in Hackney in 1741.-Pioneering Female Traveller:Fiennes never married...
were amongst those who described them. In popular culture they became a synonym for something bright but worthless.
Origin
Dolomitic Conglomerate formed during the TriassicTriassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
period (about 250 to 200 million years ago) in the Bristol
Bristol
Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...
Avon Gorge
Avon Gorge
The Avon Gorge is a 1.5-mile long gorge on the River Avon in Bristol, England. The gorge runs south to north through a limestone ridge west of Bristol city centre, and about 3 miles from the mouth of the river at Avonmouth. The gorge forms the boundary between the unitary authorities of...
as a result of clays mingling with rock debris scree
Scree
Scree, also called talus, is a term given to an accumulation of broken rock fragments at the base of crags, mountain cliffs, or valley shoulders. Landforms associated with these materials are sometimes called scree slopes or talus piles...
which had formed against the Carboniferous limestone
Carboniferous limestone
Carboniferous Limestone is a term used to describe a variety of different types of limestone occurring widely across Great Britain and Ireland which were deposited during the Dinantian epoch of the Carboniferous period. They were formed between 363 and 325 million years ago...
cliffs of the gorge. The geodes containing the Bristol Diamonds are frequently found in this conglomerate, in the areas of Bridge Valley Road, Leigh Woods
Leigh Woods
Leigh Woods is a 2 square kilometre area of woodland on the south-west side of the Avon Gorge, opposite the English city of Bristol and north of the Ashton Court estate. It has been designated as a National Nature Reserve. Small mountain biking circuits are present in the woods and the area is a...
, Sea Mills
Sea Mills, Bristol
Sea Mills is a suburb of the English port city of Bristol. It is situated some 3.5 miles north-west of the city centre, towards the seaward end of the Avon Gorge. Nearby suburbs are Shirehampton, Sneyd Park, Combe Dingle and Stoke Bishop...
and St Vincent's Rocks. The geodes were formed from quartz, either megaquartz or fibrous quartz, the diamonds themselves resulting from the dissolution of nodules of anhydrite
Anhydrite
Anhydrite is a mineral – anhydrous calcium sulfate, CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium and strontium sulfates, as might be expected from the...
leaving a void which allowed the silica crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
s to grow.
In popular culture
In William CamdenWilliam Camden
William Camden was an English antiquarian, historian, topographer, and officer of arms. He wrote the first chorographical survey of the islands of Great Britain and Ireland and the first detailed historical account of the reign of Elizabeth I of England.- Early years :Camden was born in London...
's topographical
Topography
Topography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...
survey of Great Britain and Ireland, published in 1586, the diamonds are described:
"The one of them which on the East-side overlooketh the river beareth the name of S. Vincents rock, so full of Diamants that a man may fill whole strikes or bushels of them. These are not so much set by, because they be so plenteous. For in bright and transparent colour they match the Indian Diaments, if they passe them not; in hardnesse onely they are inferior to them, but in that nature herselfe hath framed them with six cornered or foure cornered smooth sides, I thinke them therefore worthy to be had in greater admiration. The other rocke also on the West-side is likewise full of Diamants, which by the wonderfull skill and worke of nature are enclosed as young ones within the bowels of hollow and reddish flints, for heere is the earth of a red colour."
In 1654, diarist John Evelyn
John Evelyn
John Evelyn was an English writer, gardener and diarist.Evelyn's diaries or Memoirs are largely contemporaneous with those of the other noted diarist of the time, Samuel Pepys, and cast considerable light on the art, culture and politics of the time John Evelyn (31 October 1620 – 27 February...
visited Bristol and, like many other visitors, went hunting for the diamonds, "what was most stupendous to me was the rock of St. Vincent, the precipice whereof is equal to anything of that nature I have seen in the most confragous cataracts of the Alps. Here we went searching for Bristol diamonds and to the Hotwells at its foot." The late seventeenth century English
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
traveller Celia Fiennes
Celia Fiennes
Celia Fiennes was an English traveller. Born in Wiltshire, she was the daughter of an English Civil War Parliamentarian Colonel, who was in turn the second son of the William Fiennes, 1st Viscount Saye and Sele. Celia Fiennes died in Hackney in 1741.-Pioneering Female Traveller:Fiennes never married...
described them,
"This is just by St Vincents Rocks yt are Great Clifts wch seeme as bounds to ye river Aven, this Channell was hewn out of those Rocks. They Digg ye Bristol Diamonds wch Look very Bright and sparkling and in their native Rudeness have a great Lustre and are pointed and Like ye Diamond Cutting; I had a piece just as it Came out of ye Rock wth ye Rock on ye back side and it appeared to me as a Cluster of Diamonds polish'd and jrregularly Cut."
The central hall of Goldney Grotto, an ornate feature of the 18th century gardens at Goldney House, Clifton
Clifton, Bristol
Clifton is a suburb of the City of Bristol in England, and the name of both one of the city's thirty-five council wards. The Clifton ward also includes the areas of Cliftonwood and Hotwells...
, contains columns covered with the crystals. The diamonds were often referred to "as examples of worthless but deceptive brilliance." Thomas Carlyle
Thomas Carlyle
Thomas Carlyle was a Scottish satirical writer, essayist, historian and teacher during the Victorian era.He called economics "the dismal science", wrote articles for the Edinburgh Encyclopedia, and became a controversial social commentator.Coming from a strict Calvinist family, Carlyle was...
, in a letter dated 1828, used them in a simile
Simile
A simile is a figure of speech that directly compares two different things, usually by employing the words "like", "as". Even though both similes and metaphors are forms of comparison, similes indirectly compare the two ideas and allow them to remain distinct in spite of their similarities, whereas...
disparaging the latest work of the poet Thomas Moore
Thomas Moore
Thomas Moore was an Irish poet, singer, songwriter, and entertainer, now best remembered for the lyrics of The Minstrel Boy and The Last Rose of Summer. He was responsible, with John Murray, for burning Lord Byron's memoirs after his death...
, as being "resplendent with gold-leaf and Bristol diamonds, and inwardly made of mere Potter's-clay."
Bristol Diamonds became popular souvenir
Souvenir
A souvenir , memento, keepsake or token of remembrance is an object a person acquires for the memories the owner associates with it. The term souvenir brings to mind the mass-produced kitsch that is the main commodity of souvenir and gift shops in many tourist traps around the world...
s for visitors to the spa
Spa
The term spa is associated with water treatment which is also known as balneotherapy. Spa towns or spa resorts typically offer various health treatments. The belief in the curative powers of mineral waters goes back to prehistoric times. Such practices have been popular worldwide, but are...
at Hotwells in the early nineteenth century, and were also used for jewellery, although Benjamin Silliman, a nineteenth century American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
traveller, considered them overpriced. They were described by Chilcott, in Chilcott's new guide to Bristol, Clifton and the Hotwells (1826) as sometimes "exceedingly clear and brilliant, and of so hard a nature as to cut glass ... sometimes tinged with yellow, sometimes purple".
Sample Bristol Diamonds were exhibited as part of the geology of Bristol section at London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
's The Great Exhibition
The Great Exhibition
The Great Exhibition of the Works of Industry of all Nations or The Great Exhibition, sometimes referred to as the Crystal Palace Exhibition in reference to the temporary structure in which it was held, was an international exhibition that took place in Hyde Park, London, from 1 May to 15 October...
, in 1851.
Bristol Diamonds was the title of a popular one act farce
Farce
In theatre, a farce is a comedy which aims at entertaining the audience by means of unlikely, extravagant, and improbable situations, disguise and mistaken identity, verbal humour of varying degrees of sophistication, which may include word play, and a fast-paced plot whose speed usually increases,...
by nineteenth century dramatist John Oxenford
John Oxenford
John Oxenford , English dramatist, was born at Camberwell, London, England.-Life:He began his literary career by writing on finance...
, premièred at St James's Theatre
St James's Theatre
The St James's Theatre was a 1,200-seat theatre located in King Street, at Duke Street, St James's, London. The elaborate theatre was designed with a neo-classical exterior and a Louis XIV style interior by Samuel Beazley and built by the partnership of Peto & Grissell for the tenor and theatre...
, London in 1862 and described by the Daily News
Daily News (UK)
The Daily News was a national daily newspaper in the United Kingdom.The News was founded in 1846 by Charles Dickens, who also served as the newspaper's first editor. It was conceived as a radical rival to the right-wing Morning Chronicle. The paper was not at first a commercial success...
as a "capital farce, with a good plot, and most humorous dialogue." Nineteenth century romantic novelist Emma Marshall published Bristol diamonds: or, The Hot wells in the year 1773, the plot of which centred on a brooch made of Bristol Diamonds.
Eighteenth and nineteenth century collection and quarrying in the Avon Gorge have exhausted the once ready supply of Bristol Diamonds, although some are still occasionally discovered. Examples can be seen at the University of Bristol
University of Bristol
The University of Bristol is a public research university located in Bristol, United Kingdom. One of the so-called "red brick" universities, it received its Royal Charter in 1909, although its predecessor institution, University College, Bristol, had been in existence since 1876.The University is...
's Geology Museum and at Bristol City Museum.