Skip to main content
Select Source:

agate

agate (ăg´Ĭt), translucent, cryptocrystalline variety of quartz and a subvariety of chalcedony. Agates are identical in chemical structure to jasper, flint, chert, petrified wood, and tiger's-eye, and are often found in association with opal. The colorful, banded rocks are used as a semiprecious gemstone and in the manufacture of grinding equipment. An agate's banding forms as silica from solution is slowly deposited into cavities and veins in older rock. The stones can be artificially stained to produce combinations of color more vivid than those found in the natural state. The cutting and staining of agates has long been centered at Idar-Oberstein, Germany. Important sources of agate are Brazil, Uruguay, and the United States (Oregon, Washington, and around Lake Superior). The moss agate or mocha stone contains visible impurities in the form of dendritic shapes that resemble moss. See onyx.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"agate." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 22 May. 2018 <http://www.encyclopedia.com>.

"agate." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (May 22, 2018). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/agate

"agate." The Columbia Encyclopedia, 6th ed.. . Retrieved May 22, 2018 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/agate

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Agate (or Achates)

Agate (or Achates)

According to ancient tradition, this precious stone protected against the biting of scorpions or serpents, soothed the mind, drove away contagion, and put a stop to thunder and lightning. It was also said to dispose the wearer to solitude, promote eloquence, and secure the favor of princes. It gave victory over enemies to those who wore it.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Agate (or Achates)." Encyclopedia of Occultism and Parapsychology. . Encyclopedia.com. 22 May. 2018 <http://www.encyclopedia.com>.

"Agate (or Achates)." Encyclopedia of Occultism and Parapsychology. . Encyclopedia.com. (May 22, 2018). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/agate-or-achates

"Agate (or Achates)." Encyclopedia of Occultism and Parapsychology. . Retrieved May 22, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/agate-or-achates

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

agate

agate (mocha stone) Variety of chalcedonic silica (SiO2) that is cryptocrystalline. It is similar to chalcedony except that impurities of iron and manganese may give it a distinct colour banding which is frequently precipitated in concentric zones. Moss agate contains delicate, fern-like, dendritic patterns. Agates may be cut and polished as decorative stones.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"agate." A Dictionary of Earth Sciences. . Encyclopedia.com. 22 May. 2018 <http://www.encyclopedia.com>.

"agate." A Dictionary of Earth Sciences. . Encyclopedia.com. (May 22, 2018). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/agate

"agate." A Dictionary of Earth Sciences. . Retrieved May 22, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/agate

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

agate

ag·ate / ˈagit/ • n. an ornamental stone consisting of a hard variety of chalcedony, typically banded in appearance. ∎  a colored toy marble resembling a banded gemstone.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"agate." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 22 May. 2018 <http://www.encyclopedia.com>.

"agate." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. (May 22, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/agate-0

"agate." The Oxford Pocket Dictionary of Current English. . Retrieved May 22, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/agate-0

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

agate

agate Microscrystalline form of quartz with parallel bands of colour. It is regarded as a semi-precious stone and is used for making jewellery. Hardness c.6.5; r.d. c.2.6.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"agate." World Encyclopedia. . Encyclopedia.com. 22 May. 2018 <http://www.encyclopedia.com>.

"agate." World Encyclopedia. . Encyclopedia.com. (May 22, 2018). http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/agate

"agate." World Encyclopedia. . Retrieved May 22, 2018 from Encyclopedia.com: http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/agate

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

agate

agate variety of chalcedony. XVI. — (O)F. — L. achātēs — Gr. akhā́tēs.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"agate." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. 22 May. 2018 <http://www.encyclopedia.com>.

"agate." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. (May 22, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/agate-1

"agate." The Concise Oxford Dictionary of English Etymology. . Retrieved May 22, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/agate-1

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

agate

agate •adit •bandit, pandit •accredit, credit, edit, subedit •Chindit • conduit •audit, plaudit •pundit • refit • misfit • benefit •profit, prophet, soffit •forfeit • outfit • Tophet • photofit •buffet, tuffet •comfit • counterfeit • surfeit • agate •margate, target •frigate • Tlingit • hogget •drugget, nugget •Brigitte • gadget • eejit •Bridget, digit, fidget, midget, widget •budget •Blackett, bracket, jacket, packet, placket, racket •blanket • gasket • bedjacket •straitjacket • lifejacket • leatherjacket •downmarket, market, upmarket •basket, casket •breadbasket • Euromarket •Newmarket • hypermarket •Becket, Beckett •cricket, midwicket, picket, picquet, piquet, pricket, snicket, thicket, ticket, wicket •trinket •biscuit, brisket, frisket •identikit •brocket, crocket, Crockett, docket, locket, pocket, rocket, socket, sprocket •airpocket • pickpocket • skyrocket •toolkit •bucket, Nantucket, tucket •Blunkett, junket •musket • rust bucket •circuit, short-circuit

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"agate." Oxford Dictionary of Rhymes. . Encyclopedia.com. 22 May. 2018 <http://www.encyclopedia.com>.

"agate." Oxford Dictionary of Rhymes. . Encyclopedia.com. (May 22, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/agate

"agate." Oxford Dictionary of Rhymes. . Retrieved May 22, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/agate

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.