Pearl - Revision history

MDerrick: /* Physical and Chemical Properties */

2022-12-16T18:26:46Z

Physical and Chemical Properties

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	* Density = 2.68-2.4 g/ml		* Density = 2.68-2.4 g/ml
	* Refractive index = 1.530 - 1.685		* Refractive index = 1.530 - 1.685
			* Birefringence = 0.155
	* Fluorescence = variable; inert to strong light blue, yellow, green or pink under LW and SW		* Fluorescence = variable; inert to strong light blue, yellow, green or pink under LW and SW
	* Both natural and cultured pearls may feel gritty when rubbed against a tooth		* Both natural and cultured pearls may feel gritty when rubbed against a tooth

MDerrick at 18:25, 16 December 2022

2022-12-16T18:25:54Z

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	* Most exhibit a sky -blue color fluorescence		* Most exhibit a sky -blue color fluorescence
	* Mohs Hardness = 3 - 4		* Mohs Hardness = 3 - 4
	* Density = 2.68-2.4		* Density = 2.68-2.4 g/ml
			* Refractive index = 1.530 - 1.685
			* Fluorescence = variable; inert to strong light blue, yellow, green or pink under LW and SW
			* Both natural and cultured pearls may feel gritty when rubbed against a tooth

	== Resources and Citations ==		== Resources and Citations ==

	* Oppi Untracht, ''Jewelry Concepts and Technology'', Doubleday & Co., Inc., New York City, 1985 Comment: specific gravity for Oriental pearls = 2.68-2.74, cultured = 2.70-2.79, freshwater pearls = 2.68; average hardness = Mohs 3-4; double refraction = 1.57		* Oppi Untracht, ''Jewelry Concepts and Technology'', Doubleday & Co., Inc., New York City, 1985 Comment: specific gravity for Oriental pearls = 2.68-2.74, cultured = 2.70-2.79, freshwater pearls = 2.68; average hardness = Mohs 3-4; double refraction = 1.57
			* Gem Identification Lab Manual, Gemological Institute of America, 2016.
	* Jack Odgen, ''Jewellery of the Ancient World'', Rizzoli International Publications Inc., New York City, 1982		* Jack Odgen, ''Jewellery of the Ancient World'', Rizzoli International Publications Inc., New York City, 1982

	* ''Encyclopedia Britannica'', http://www.britannica.com Comment: "pearl." Accessed 23 Dec. 2004 .		* ''Encyclopedia Britannica'', http://www.britannica.com Comment: "pearl." Accessed 23 Dec. 2004 .

	* Website: http://www.geo.utexas.edu/courses/347k/redesign/gem_notes/pearl/pearl_main.htm -Gives density of natural pearls as 2.66-2.78 and cultured pearls as 2.72-2.78		* Website: http://www.geo.utexas.edu/courses/347k/redesign/gem_notes/pearl/pearl_main.htm -Gives density of natural pearls as 2.66-2.78 and cultured pearls as 2.72-2.78

	* Wikipedia: http://en.wikipedia.org/wiki/Pearl (Accessed Nov. 9, 2005)		* Wikipedia: http://en.wikipedia.org/wiki/Pearl (Accessed Nov. 9, 2005)

	* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971		* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971

	* ''Caring for your Collections'', Arthur W Schulz (ed.), Harry N. Abrams, Inc. , New York, 1992		* ''Caring for your Collections'', Arthur W Schulz (ed.), Harry N. Abrams, Inc. , New York, 1992

	* Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000		* Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000

MDerrick at 15:43, 4 August 2022

2022-08-04T15:43:46Z

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	[[File:1986.764-CR2755-d1.jpg\|thumb\|Brooch with pearls<br>MFA# 1986.764]]		[[File:1986.764-CR2755-d1.jpg\|thumb\|Brooch with pearls<br>MFA# 1986.764]]
	== Description ==		== Description ==
			[[File:Pearl headdress.jpg\|thumb\|Pearl Headdress<br>MFA# 51.355]]
			A smooth, opaque, iridescent gem formed as a multilayered [[nacre\|nacre]] deposit around foreign matter embedded in the shells of mollusks. Nacre is composed of [[aragonite\|aragonite]] crystals bound together with [[conchiolin\|conchiolin]]. The nacre is built up in thin, concentric layers that grow at rates of less than a millimeter per year. Large, natural pearls a rarity with the largest known pearl weighing 93 grams. The shape of the pearl depends on the shape of the embedded inclusion so most natural pearls are not spherical. Salt-water pearls, also called Oriental pearls, are found in the Persian Gulf, Gulf on Mannar, Myanmar, Tahiti, Borneo, New Guinea, Venezuela, and Australia. Since 1920, pearls have been cultured commercially.

	A smooth, opaque, iridescent gem formed as a multilayered [[nacre\|nacre]] deposit around foreign matter embedded in the shells of mollusks. Nacre is composed of [[aragonite\|aragonite]] crystals bound together with [[conchiolin\|conchiolin]]. The nacre is built up in thin, concentric layers that grow at rates of less than a millimeter per year. Large, natural pearls a rarity with the largest known pearl weighing 93 grams. The shape of the pearl depends on the shape of the embedded inclusion so most natural pearls are not spherical. Salt-water pearls, also called Oriental pearls, are found in the Persian Gulf, Gulf on Mannar, Myanmar, Tahiti, Borneo, New Guinea, Venezuela, and Australia. Since 1920, pearls have been cultured commercially.
	~~[[File:Pearl headdress.jpg\|thumb\|Pearl Headdress<br>MFA# 51.355]]~~
	See also [[pearl%2C%20cultured\|pearl, cultured]], and [[pearl%2C%20freshwater\|pearl, freshwater]].		See also [[pearl%2C%20cultured\|pearl, cultured]], and [[pearl%2C%20freshwater\|pearl, freshwater]].
			[[File:Pearl earrings.jpg\|thumb\|Pearl earrings<br>MFA# 43.2122]]
	== Synonyms and Related Terms ==		== Synonyms and Related Terms ==

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	== Risks ==		== Risks ==
	~~[[File:Pearl earrings.jpg\|thumb\|Pearl earrings<br>MFA# 43.2122]]~~
	Easily damaged by acids. Deteriorates at low humidities. Easily scratched. May be discolored by soap or skin oil.		* Easily damaged by acids.
			* Deteriorates at low humidities.
			* Easily scratched.
			* May be discolored by soap or skin oil.
	== Physical and Chemical Properties ==		== Physical and Chemical Properties ==

MDerrick at 18:16, 12 August 2020

2020-08-12T18:16:41Z

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	== Risks ==		== Risks ==
			[[File:Pearl earrings.jpg\|thumb\|Pearl earrings<br>MFA# 43.2122]]
	Easily damaged by acids. Deteriorates at low humidities. Easily scratched. May be discolored by soap or skin oil.		Easily damaged by acids. Deteriorates at low humidities. Easily scratched. May be discolored by soap or skin oil.
	== Physical and Chemical Properties ==		== Physical and Chemical Properties ==

MDerrick at 18:11, 12 August 2020

2020-08-12T18:11:12Z

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	A smooth, opaque, iridescent gem formed as a multilayered [[nacre\|nacre]] deposit around foreign matter embedded in the shells of mollusks. Nacre is composed of [[aragonite\|aragonite]] crystals bound together with [[conchiolin\|conchiolin]]. The nacre is built up in thin, concentric layers that grow at rates of less than a millimeter per year. Large, natural pearls a rarity with the largest known pearl weighing 93 grams. The shape of the pearl depends on the shape of the embedded inclusion so most natural pearls are not spherical. Salt-water pearls, also called Oriental pearls, are found in the Persian Gulf, Gulf on Mannar, Myanmar, Tahiti, Borneo, New Guinea, Venezuela, and Australia. Since 1920, pearls have been cultured commercially.		A smooth, opaque, iridescent gem formed as a multilayered [[nacre\|nacre]] deposit around foreign matter embedded in the shells of mollusks. Nacre is composed of [[aragonite\|aragonite]] crystals bound together with [[conchiolin\|conchiolin]]. The nacre is built up in thin, concentric layers that grow at rates of less than a millimeter per year. Large, natural pearls a rarity with the largest known pearl weighing 93 grams. The shape of the pearl depends on the shape of the embedded inclusion so most natural pearls are not spherical. Salt-water pearls, also called Oriental pearls, are found in the Persian Gulf, Gulf on Mannar, Myanmar, Tahiti, Borneo, New Guinea, Venezuela, and Australia. Since 1920, pearls have been cultured commercially.
			[[File:Pearl headdress.jpg\|thumb\|Pearl Headdress<br>MFA# 51.355]]
	See also [[pearl%2C%20cultured\|pearl, cultured]], and [[pearl%2C%20freshwater\|pearl, freshwater]].		See also [[pearl%2C%20cultured\|pearl, cultured]], and [[pearl%2C%20freshwater\|pearl, freshwater]].

MDerrick at 18:07, 12 August 2020

2020-08-12T18:07:05Z

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	pearls; natural pearls; Oriental pearls; perle (Dan., Fr.); Perle (Deut.); perla (Esp.); parel (Ned.); pérola (Port.); parel (Ned.)		pearls; natural pearls; Oriental pearls; perle (Dan., Fr.); Perle (Deut.); perla (Esp.); parel (Ned.); pérola (Port.); parel (Ned.)

	== ~~Other Properties~~ ==		== Risks ==

	~~Specific gravity for natural and Oriental pearls = 2.68-2.74; for cultured pearls = 2~~.~~70-2~~.~~79; and for freshwater pearls = 2~~.68		Easily damaged by acids. Deteriorates at low humidities. Easily scratched. May be discolored by soap or skin oil.
			== Physical and Chemical Properties ==
	~~Texture: slightly rough~~

	~~Luster: pearly (iridescent)~~

	~~Color: white, pale yellow, pink, gray, brown, black~~

	~~Most exhibit a sky -blue color fluorescence~~

	~~{\| class="wikitable"~~
	\|-
	~~! scope="row"\| Mohs Hardness~~
	~~\| 3 - 4~~
	\|-
	~~! scope="row"\| Density~~
	~~\| 2~~.~~68-2.4~~
	\|}

	== ~~Hazards~~ and ~~Safety~~ ==

	~~Easily damaged by acids~~. ~~Deteriorates at low humidities~~. ~~Easily scratched~~. ~~May be discolored by soap or skin oil~~.		* Specific gravity for natural and Oriental pearls = 2.68-2.74; for cultured pearls = 2.70-2.79; and for freshwater pearls = 2.68
			* Texture: slightly rough
			* Luster: pearly (iridescent)
			* Color: white, pale yellow, pink, gray, brown, black
			* Most exhibit a sky -blue color fluorescence
			* Mohs Hardness = 3 - 4
			* Density = 2.68-2.4

	== ~~Sources Checked for Data in Record~~ ==		== Resources and Citations ==

	* Oppi Untracht, ''Jewelry Concepts and Technology'', Doubleday & Co., Inc., New York City, 1985 Comment: specific gravity for Oriental pearls = 2.68-2.74, cultured = 2.70-2.79, freshwater pearls = 2.68; average hardness = Mohs 3-4; double refraction = 1.57		* Oppi Untracht, ''Jewelry Concepts and Technology'', Doubleday & Co., Inc., New York City, 1985 Comment: specific gravity for Oriental pearls = 2.68-2.74, cultured = 2.70-2.79, freshwater pearls = 2.68; average hardness = Mohs 3-4; double refraction = 1.57
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	* Jack Odgen, ''Jewellery of the Ancient World'', Rizzoli International Publications Inc., New York City, 1982		* Jack Odgen, ''Jewellery of the Ancient World'', Rizzoli International Publications Inc., New York City, 1982

	* ''Encyclopedia Britannica'', http://www.britannica.com Comment: "pearl." ~~Encyclopædia Britannica. 2004. Encyclopædia Britannica Premium Service.~~ 23 Dec. 2004 .		* ''Encyclopedia Britannica'', http://www.britannica.com Comment: "pearl." Accessed 23 Dec. 2004 .

	* Website ~~address 1 Comment~~: http://www.geo.utexas.edu/courses/347k/redesign/gem_notes/pearl/pearl_main.htm -Gives density of natural pearls as 2.66-2.78 and cultured pearls as 2.72-2.78		* Website: http://www.geo.utexas.edu/courses/347k/redesign/gem_notes/pearl/pearl_main.htm -Gives density of natural pearls as 2.66-2.78 and cultured pearls as 2.72-2.78

	* Wikipedia~~, the free encyclopedia, at http://www.wikipedia.com Comment~~: http://en.wikipedia.org/wiki/Pearl (Accessed Nov. 9, 2005)		* Wikipedia: http://en.wikipedia.org/wiki/Pearl (Accessed Nov. 9, 2005)

	* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971		* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971

MDerrick at 18:04, 12 August 2020

2020-08-12T18:04:20Z

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	[[File:1986.764-CR2755-d1.jpg\|thumb\|]]		[[File:1986.764-CR2755-d1.jpg\|thumb\|Brooch with pearls<br>MFA# 1986.764]]
	== Description ==		== Description ==

Jruggiero: Text replace - "\[http:\/\/cameo\.mfa\.org\/materials\/fullrecord\.asp\?name=([^\s]+)\s(.*)\]" to "$2"

2016-05-10T16:09:58Z

Text replace - "\[http:\/\/cameo\.mfa\.org\/materials\/fullrecord\.asp\?name=([^\s]+)\s(.*)\]" to "$2"

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	== Description ==		== Description ==

	A smooth, opaque, iridescent gem formed as a multilayered [~~http://cameo.mfa.org/materials/fullrecord.asp?name=~~nacre nacre] deposit around foreign matter embedded in the shells of mollusks. Nacre is composed of [~~http://cameo.mfa.org/materials/fullrecord.asp?name=~~aragonite aragonite] crystals bound together with [~~http://cameo.mfa.org/materials/fullrecord.asp?name=~~conchiolin conchiolin]. The nacre is built up in thin, concentric layers that grow at rates of less than a millimeter per year. Large, natural pearls a rarity with the largest known pearl weighing 93 grams. The shape of the pearl depends on the shape of the embedded inclusion so most natural pearls are not spherical. Salt-water pearls, also called Oriental pearls, are found in the Persian Gulf, Gulf on Mannar, Myanmar, Tahiti, Borneo, New Guinea, Venezuela, and Australia. Since 1920, pearls have been cultured commercially.		A smooth, opaque, iridescent gem formed as a multilayered [[nacre\|nacre]] deposit around foreign matter embedded in the shells of mollusks. Nacre is composed of [[aragonite\|aragonite]] crystals bound together with [[conchiolin\|conchiolin]]. The nacre is built up in thin, concentric layers that grow at rates of less than a millimeter per year. Large, natural pearls a rarity with the largest known pearl weighing 93 grams. The shape of the pearl depends on the shape of the embedded inclusion so most natural pearls are not spherical. Salt-water pearls, also called Oriental pearls, are found in the Persian Gulf, Gulf on Mannar, Myanmar, Tahiti, Borneo, New Guinea, Venezuela, and Australia. Since 1920, pearls have been cultured commercially.

	See also [~~http://cameo.mfa.org/materials/fullrecord.asp?name=~~pearl%2C%20cultured pearl, cultured], and [~~http://cameo.mfa.org/materials/fullrecord.asp?name=~~pearl%2C%20freshwater pearl, freshwater].		See also [[pearl%2C%20cultured\|pearl, cultured]], and [[pearl%2C%20freshwater\|pearl, freshwater]].

	== Synonyms and Related Terms ==		== Synonyms and Related Terms ==

Jruggiero: Text replace - "== Authority ==" to "== Sources Checked for Data in Record =="

2016-05-01T19:42:00Z

Text replace - "== Authority ==" to "== Sources Checked for Data in Record =="

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	Easily damaged by acids. Deteriorates at low humidities. Easily scratched. May be discolored by soap or skin oil.		Easily damaged by acids. Deteriorates at low humidities. Easily scratched. May be discolored by soap or skin oil.

	== ~~Authority~~ ==		== Sources Checked for Data in Record ==

	* Oppi Untracht, ''Jewelry Concepts and Technology'', Doubleday & Co., Inc., New York City, 1985 Comment: specific gravity for Oriental pearls = 2.68-2.74, cultured = 2.70-2.79, freshwater pearls = 2.68; average hardness = Mohs 3-4; double refraction = 1.57		* Oppi Untracht, ''Jewelry Concepts and Technology'', Doubleday & Co., Inc., New York City, 1985 Comment: specific gravity for Oriental pearls = 2.68-2.74, cultured = 2.70-2.79, freshwater pearls = 2.68; average hardness = Mohs 3-4; double refraction = 1.57

Unknown user at 12:51, 24 July 2013

2013-07-24T12:51:01Z

← Older revision		Revision as of 13:11, 12 August 2020
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	A smooth, opaque, iridescent gem formed as a multilayered [[nacre\|nacre]] deposit around foreign matter embedded in the shells of mollusks. Nacre is composed of [[aragonite\|aragonite]] crystals bound together with [[conchiolin\|conchiolin]]. The nacre is built up in thin, concentric layers that grow at rates of less than a millimeter per year. Large, natural pearls a rarity with the largest known pearl weighing 93 grams. The shape of the pearl depends on the shape of the embedded inclusion so most natural pearls are not spherical. Salt-water pearls, also called Oriental pearls, are found in the Persian Gulf, Gulf on Mannar, Myanmar, Tahiti, Borneo, New Guinea, Venezuela, and Australia. Since 1920, pearls have been cultured commercially.		A smooth, opaque, iridescent gem formed as a multilayered [[nacre\|nacre]] deposit around foreign matter embedded in the shells of mollusks. Nacre is composed of [[aragonite\|aragonite]] crystals bound together with [[conchiolin\|conchiolin]]. The nacre is built up in thin, concentric layers that grow at rates of less than a millimeter per year. Large, natural pearls a rarity with the largest known pearl weighing 93 grams. The shape of the pearl depends on the shape of the embedded inclusion so most natural pearls are not spherical. Salt-water pearls, also called Oriental pearls, are found in the Persian Gulf, Gulf on Mannar, Myanmar, Tahiti, Borneo, New Guinea, Venezuela, and Australia. Since 1920, pearls have been cultured commercially.
			[[File:Pearl headdress.jpg\|thumb\|Pearl Headdress<br>MFA# 51.355]]
	See also [[pearl%2C%20cultured\|pearl, cultured]], and [[pearl%2C%20freshwater\|pearl, freshwater]].		See also [[pearl%2C%20cultured\|pearl, cultured]], and [[pearl%2C%20freshwater\|pearl, freshwater]].

← Older revision		Revision as of 07:51, 24 July 2013
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	A smooth, opaque, iridescent gem formed as a multilayered [http://cameo.mfa.org/materials/fullrecord.asp?name=nacre nacre] deposit around foreign matter embedded in the shells of mollusks. Nacre is composed of [http://cameo.mfa.org/materials/fullrecord.asp?name=aragonite aragonite] crystals bound together with [http://cameo.mfa.org/materials/fullrecord.asp?name=conchiolin conchiolin]. The nacre is built up in thin, concentric layers that grow at rates of less than a millimeter per year. Large, natural pearls a rarity with the largest known pearl weighing 93 grams. The shape of the pearl depends on the shape of the embedded inclusion so most natural pearls are not spherical. Salt-water pearls, also called Oriental pearls, are found in the Persian Gulf, Gulf on Mannar, Myanmar, Tahiti, Borneo, New Guinea, Venezuela, and Australia. Since 1920, pearls have been cultured commercially.		A smooth, opaque, iridescent gem formed as a multilayered [http://cameo.mfa.org/materials/fullrecord.asp?name=nacre nacre] deposit around foreign matter embedded in the shells of mollusks. Nacre is composed of [http://cameo.mfa.org/materials/fullrecord.asp?name=aragonite aragonite] crystals bound together with [http://cameo.mfa.org/materials/fullrecord.asp?name=conchiolin conchiolin]. The nacre is built up in thin, concentric layers that grow at rates of less than a millimeter per year. Large, natural pearls a rarity with the largest known pearl weighing 93 grams. The shape of the pearl depends on the shape of the embedded inclusion so most natural pearls are not spherical. Salt-water pearls, also called Oriental pearls, are found in the Persian Gulf, Gulf on Mannar, Myanmar, Tahiti, Borneo, New Guinea, Venezuela, and Australia. Since 1920, pearls have been cultured commercially.

	See also [http://cameo.mfa.org/materials/fullrecord.asp?name=pearl~~, cultured~~ pearl, cultured], and [http://cameo.mfa.org/materials/fullrecord.asp?name=pearl~~, freshwater~~ pearl, freshwater].		See also [http://cameo.mfa.org/materials/fullrecord.asp?name=pearl%2C%20cultured pearl, cultured], and [http://cameo.mfa.org/materials/fullrecord.asp?name=pearl%2C%20freshwater pearl, freshwater].

	== Synonyms and Related Terms ==		== Synonyms and Related Terms ==

	pearls; natural pearls; Oriental pearls; perle (Dan., Fr.); Perle (Deut.); perla (Esp.); parel (Ned.); ~~prola~~ (Port.); parel (Ned.)		pearls; natural pearls; Oriental pearls; perle (Dan., Fr.); Perle (Deut.); perla (Esp.); parel (Ned.); pérola (Port.); parel (Ned.)

	== Other Properties ==		== Other Properties ==
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	== Authority ==		== Authority ==

	* ~~Oppi Untracht,~~ Oppi Untracht, ''Jewelry Concepts and Technology'', Doubleday & Co., Inc., New York City, 1985 Comment: specific gravity for Oriental pearls = 2.68-2.74, cultured = 2.70-2.79, freshwater pearls = 2.68; average hardness = Mohs 3-4; double refraction = 1.57		* Oppi Untracht, ''Jewelry Concepts and Technology'', Doubleday & Co., Inc., New York City, 1985 Comment: specific gravity for Oriental pearls = 2.68-2.74, cultured = 2.70-2.79, freshwater pearls = 2.68; average hardness = Mohs 3-4; double refraction = 1.57

	* ~~Jack Odgen,~~ Jack Odgen, ''Jewellery of the Ancient World'', Rizzoli International Publications Inc., New York City, 1982		* Jack Odgen, ''Jewellery of the Ancient World'', Rizzoli International Publications Inc., New York City, 1982

	* ''Encyclopedia Britannica'', http://www.britannica.com Comment: "pearl." ~~Encyclopdia~~ Britannica. 2004. ~~Encyclopdia~~ Britannica Premium Service. 23 Dec. 2004 .		* ''Encyclopedia Britannica'', http://www.britannica.com Comment: "pearl." Encyclopædia Britannica. 2004. Encyclopædia Britannica Premium Service. 23 Dec. 2004 .

	* ~~Website address 1,~~ Website address 1 Comment: http://www.geo.utexas.edu/courses/347k/redesign/gem_notes/pearl/pearl_main.htm -Gives density of natural pearls as 2.66-2.78 and cultured pearls as 2.72-2.78		* Website address 1 Comment: http://www.geo.utexas.edu/courses/347k/redesign/gem_notes/pearl/pearl_main.htm -Gives density of natural pearls as 2.66-2.78 and cultured pearls as 2.72-2.78

	* Wikipedia, the free encyclopedia, at http://www.wikipedia.com Comment: http://en.wikipedia.org/wiki/Pearl (Accessed Nov. 9, 2005)		* Wikipedia, the free encyclopedia, at http://www.wikipedia.com Comment: http://en.wikipedia.org/wiki/Pearl (Accessed Nov. 9, 2005)

	* ~~G.S.Brady,~~ G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971		* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971

	* ''Caring for your Collections'', Arthur W Schulz (ed.), Harry N. Abrams, Inc. , New York, 1992		* ''Caring for your Collections'', Arthur W Schulz (ed.), Harry N. Abrams, Inc. , New York, 1992