Editing Agate (section)

== Varieties (by locality) ==
Agates are very common, and they have been found on every continent, including Antarctica. In addition to names used to describe their structure, numerous geological, local, and trade names are applied to agates from different localities.<ref name="pabian" />{{rp|pp=7–9}} Below is a list of known agate localities and the names of the agates that are found there. This list is not exhaustive.

=== Africa ===
* ''Blue lace agate'' is a pale blue and white lace agate found primarily in [[Namibia]]. These agates formed in dolomite associated with igneous rock.
* ''Botswana agates'' are found in [[basalt]]ic rocks of the [[Permian]] age in [[Botswana]]. They feature contrasting bands of purple, pink, black, grey, and white. Like Lake Superior agates, they are typically small, averaging <!--CheckU-->{{convert|2.5|–|5|cm|in|abbr=on}} in diameter.
* ''Malawi agates'' are typically bright red or orange with contrasting white bands, but some are pink and blue. They can be found in [[Malawi]], and they likely formed in volcanic rock of Permian age.
* Agates have also been found in [[Egypt]], [[Madagascar]], [[South Africa]], and [[Zimbabwe]].<ref name="pabian" />{{rp|pp=131–137}}
<gallery mode="packed" heights="130px">
Blue Lace Agate from Namibia (polished).jpg|Blue lace agate
Agat - Bobonong, Botswana.jpg|Botswana agate
Malawi Agate (Malawi, southeastern Africa) (32734668126).jpg|Malawi agate
</gallery>

=== Antarctica ===
* White and clear banded agates have been found by scientists at [[Bellingshausen Station]], a Russian outpost on [[King George Island (South Shetland Islands)|King George Island]].<ref>{{cite web |title=Collins Harbour, King George Island, South Shetland Islands, Antarctic Peninsula, Western Antarctica, Antarctica |url=https://www.mindat.org/loc-420174.html |website=mindat.org |publisher=Hudson Institute of Mineralogy |access-date=16 February 2025}}</ref>
[[File:Agate (Tertiary; Agate Bay, King George Island, South Shetland Islands) 1.jpg|thumb|center|215px|Agate from King George Island, Antarctica]]

=== Asia ===
* India has produced agates since as early as the 11th century. These include carnelian agates, moss agates, and dendritic agates.
* Yemen is home to a variety of agate called ''mocha stone'', named after the port city of [[Mokha|Mocha]] (also spelled Mokha or Mukha) on the [[Red Sea]]. These agates likely formed in [[tuff]] deposits of [[Chattian|Late Oligocene]] and [[Early Miocene]] age.
* Agates have also been found in [[Iran]], [[Mongolia]], [[China]],<ref name="pabian" />{{rp|pp=138–143}} and [[Russia]].<ref name="mindat" />
[[File:Agates Mandalgobi (2).jpg|thumb|center|180px|Rough agates from the [[Gobi Desert]] in Mongolia]]

=== Australia ===
* ''Queensland agates,'' found in the State of [[Queensland]], often occur in colors that are rarely found in agates from other regions, such as green and yellow-green. They formed in basaltic lava flows of the Late Permian period. Level banding is common in Queensland agates, while inclusions are uncommon. Queensland is also home to several kinds of ''thunder egg'', which are thought to date from the [[Early Cretaceous]] period. 
* Agates have also been found in [[Tasmania]] and other regions of Australia.<ref name="pabian" />{{rp|pp=144–149}}
[[File:Agat ze strefą krustalną - Agate Creek, Queensland, Australia.jpg|thumb|center|215px|Queensland agate with level banding]]

=== Europe ===
* Agate was discovered in [[Sicily]] by the Greek scholar Theophrastus in 350 BC. At the time, Sicily was a colony of [[ancient Greece]]. The name "agate" comes from the Achates River, the Greek name for what is now known as the [[Dirillo|Dirillo River]]. Agates in Sicily formed in balsaltic lavas and pyroclastic rocks of the [[Pliocene|Pilocene]] epoch.
* [[Germany]] is a well-known historic source of agate. Agates mined from volcanic rock of the Permian period have been processed in [[Idar-Oberstein]] since at least 1375, but possibly as early as the [[Roman Empire]]. Agates from the Idar-Oberstein area are often red and pink, but other colors have also been observed. Many museum specimens include features such as eyes, tubes, moss, plumes, and sagenite. 
* [[Scotland]] is an abundant source of a wide variety of agates. There are at least 50 main agate localities in Scotland. Scottish agates have been popular in jewelry for several hundred years, particularly during the [[Victorian era]]. They formed in two types of rock: andesite from the [[Early Devonian]] period and basalt from the [[Tertiary]] period. The andesite deposits are more significant and extend from [[Stonehaven]] in the northeast to just south of [[Ayr]] in the southwest. The basaltic agates are confined to the islands off the west coast of Scotland and are collectively called the ''Small Isles agates''. The colors of Scottish agates vary, and bands may be different shades of blue, grey, purple, pink, brown, orange, or red.
* ''Pot stones'' or ''potato stones'' are irregular agate nodules or geodes found in [[Bristol]] and [[Somerset]], England. They typically consist of a reddish, banded agate surrounding a hollow cavity lined with macroscopic quartz, although some are completely filled with agate. Other varieties of agate have also been found elsewhere in England.
* Agates can also be found in [[Wales]], the [[Czech Republic]], [[Poland]], [[France]],<ref name="pabian" />{{rp|pp=52–75}} and many other European countries.<ref name="mindat" />
<gallery mode="packed" heights="130px">
Agate-MCG 91225-P4150832-white.jpg|German agate from Idar-Oberstein
Agate detail, Scotland 007 (cropped).jpg|Close-up of a Scottish agate from [[Ayrshire]]
Quartz-agate (12250382174).jpg|Potato stone from England
Agate from Czech Republic (7).jpg|Agate from Czech Republic
</gallery>

=== North America ===
* ''Coldwater agates'', such as the [[Lake Michigan]] cloud agate, are sedimentary agates that formed within [[limestone]] and [[Dolomite (rock)|dolomite]] strata of marine origin. Like volcanic agates, Coldwater agates formed from silica gels that lined pockets and seams within the bedrock. These agates are typically less colorful, with banded lines of grey and white chalcedony.<ref>{{Cite book|last=Garvin|first=Paul|url=https://books.google.com/books?id=3a1XkpBGdAcC&q=Coldwater+agates&pg=PA65|title=Iowa's Minerals: Their Occurrence, Origins, Industries, and Lore|date=2010-09-13|publisher=University of Iowa Press|isbn=978-1-60938-014-4|language=en|access-date=2020-10-29|archive-date=2023-08-26|archive-url=https://web.archive.org/web/20230826164756/https://books.google.com/books?id=3a1XkpBGdAcC&q=Coldwater+agates&pg=PA65|url-status=live}}</ref>
* ''Crazy lace agate'' is a brightly colored lace agate from [[Mexico]] with a complex pattern, demonstrating randomized distribution of contour lines and circular droplets, scattered throughout the rock. The stone is typically colored red and white but is also seen to exhibit yellow and grey combinations as well.<ref>{{Cite book|last1=Atkinson|first1=Bill|url=https://books.google.com/books?id=ZSP94tREw7AC&q=Crazy+lace+agate&pg=PA165|title=Within the Stone: Photography|last2=Ackerman|first2=Diane|date=2004|publisher=BrownTrout Publishers|isbn=978-0-7631-8189-5|language=en|access-date=2020-10-29|archive-date=2023-08-26|archive-url=https://web.archive.org/web/20230826164751/https://books.google.com/books?id=ZSP94tREw7AC&q=Crazy+lace+agate&pg=PA165|url-status=live}}</ref> Crazy lace agate is a vein agate that formed in sedimentary rock of the late [[Cretaceous]] period.<ref name="pabian" />{{rp|p=121}}
* ''Dugway geodes'' are a type of thunder egg found in [[Utah]]. They are typically light grey to blue and often contain hollow cavities lined with drusy quartz.<ref name="pabian" />{{rp|p=92}}
* [[Fairburn Agate|''Fairburn agates'']] are rare fortification agates named for [[Fairburn, South Dakota]]. They are sedimentary agates that originated during the [[Pennsylvanian (geology)|Pennsylvanian]] period, and then weathered from their host rock and redeposited during the [[Oligocene]] epoch in parts of South Dakota and [[Nebraska]].<ref>{{cite web |title=Fairburn Agate |url=https://www.mindat.org/min-1441.html |website=mindat.org |publisher=Hudson Institute of Mineralogy |access-date=16 February 2025}}</ref>
* ''Laguna agate'' is a brightly colored agate variety that was first discovered in Ojo Laguna, Chihuahua, Mexico.<ref>{{Cite web |title=Laguna Agate |url=https://www.mindat.org/min-7611.html |access-date=2025-02-16 |website=www.mindat.org}}</ref> It features vibrant bands in shades of red, orange, pink, or purple. Laguna agates formed in [[andesite]] and are geologically young. They frequently contain inclusions and many exhibit parallax or shadow banding.<ref name="pabian" />{{rp|pp=114–115}}
* ''[[Lake Superior agate]]s'' are believed to be the world's oldest agates;<ref>{{cite web |title=Lake Superior Agate |url=https://www.mindat.org/min-9253.html |website=mindat.org |publisher=Hudson Institute of Mineralogy |access-date=16 February 2025}}</ref> they formed as nodules in basalt up to 1.2 billion years ago during the Late [[Precambrian]]. These agates are primarily found near the shores of [[Lake Superior]] in the [[United States|U.S.]] states of [[Minnesota]], [[Michigan]], and [[Wisconsin]], and in the [[Canada|Canadian]] province of [[Ontario]]. They are not named after the lake, but rather the Lake Superior [[Till]], the [[Pleistocene]] glacial deposit in which they are found.<ref name="pabian" />{{rp|pp=83–84}} This deposit also extends into portions of [[Iowa]], [[Nebraska]], [[Kansas]], and [[Missouri]], and Lake Superior agates have been carried south by the [[Mississippi River]] into [[Arkansas]] and [[Louisiana]]. Lake Superior agates have bands in shades of red, orange, yellow, brown, white, and grey. They can contain a variety of structural features, including eyes, tubes, sagenite, dendrites, faults, and geodes.<ref name="lynch whole book">{{Cite book |last=Lynch |first=Dan R. |title=Lake Superior Agates Field Guide |last2=Lynch |first2=Bob |date=2012 |publisher=Adventure Publications |isbn=978-1-59193-282-6}}</ref>
* ''Lysite agate'' is a vein agate named after Lysite Mountain, [[Wyoming]]. It is frequently colorful and may contain moss and plumes in addition to bands.<ref name="pabian" />{{rp|p=79}}
* ''Nebraska blue agate'' is a sedimentary agate with dendritic patterns that formed during the Oligocene epoch. It can be found throughout northwestern Nebraska and southwestern South Dakota.<ref name="pabian" />{{rp|p=80}}
* Oregon is known for several different varieties of agate. It is probably best known for its ''thunder eggs'', which form in rhyolitic ash and have a brown rhyolite shell that is usually filled with blue and white agate.<ref name="pabian" />{{rp|p=99}} ''Holley blue agate'' (also spelled "Holly blue agate") is a rare lavender to blue agate found only near [[Holley, Oregon]].<ref name="pabian" />{{rp|p=103}}
* ''[[Patuxent River stone]]'' is a red and yellow form of agate only found in [[Maryland]], where it is the state gem.<ref>{{cite web |title=Maryland State Gem - Patuxent River Stone |url=https://msa.maryland.gov/msa/mdmanual/01glance/symbols/html/gem.html |website=maryland.gov |publisher=Maryland State Archives |access-date=16 February 2025}}</ref>
* ''Sweetwater agates'' are small moss agates found in [[Miocene]] age [[sandstone]] near Sweetwater River, Wyoming. They also contain brown or black dendrites and fluoresce under [[Ultraviolet|UV]] light.<ref name="pabian" />{{rp|p=79}}
* ''Turritella agate'' is a brown fossil agate formed from the remains of an extinct species of freshwater snail ([[Elimia tenera]]) with an elongated spiral shell. The name is a misnomer; it was originally thought to be the fossil of a different genus of gastropods, [[Turritella]]. It is found in the [[Green River Formation]] of Wyoming.<ref name="turritella">{{Cite web |last=King |first=Hobart M. |title=Turritella Agate |url=https://geology.com/gemstones/turritella/ |access-date=16 February 2025 |website=geology.com}}</ref>
* Other varieties of agate have also been found in nearly every U.S. state, northern Mexico, and in the Canadian provinces of [[Nova Scotia]], [[Manitoba]], and [[British Columbia]].<ref name="pabian" />{{rp|pp=76–121}}
<gallery mode="packed" heights="130px">
Crazy Lace Agate - Macro Panorama.jpg|Crazy lace agate
Dugway Geode (Juab County, Utah, USA) 2 (34581522545).jpg|Dugway geode from Utah
Fairburn Agate (ultimately derived from the Minnelusa Formation, Pennsylvanian-Permian; collected east of the Black Hills, western South Dakota, USA) 26 (32406082220).jpg|Fairburn agate from western South Dakota
LagunaAgateFromMexico.jpg|Laguna agate
Agate nodule ("Lake Superior Agate") (floor of Lake Superior, offshore Keweenaw Peninsula, Michigan USA) 2 (33741645898).jpg|Rough Lake Superior agate from [[Keweenaw Peninsula]], Michigan
Thunder Egg Agate (Priday Blue Bed, John Day Formation, Miocene; near Madras, Oregon, USA) 3 (33992544563).jpg|Thunder egg from Oregon
Holley Blue Agate (Linn County, Oregon, USA) 9.jpg|Holley blue agate from Oregon
Elimia fossils Wyoming.jpg|alt=An irregular dark stone with a flat polished front; many white fragments of elongated, spiral, "corkscrew" shells seem to float in the dark stone|Turritella agate (''Elimia tenera'')
Chalcedony (Variety Agate)-262773.jpg|Agate from British Columbia
</gallery>

=== South America ===
* ''Brazilian agate'' is probably one of the largest agates. They can reach {{convert|0.9|m|ft|abbr=on}} in diameter and weigh over {{convert|120|kg|lb|abbr=on}}. Brazilian agate is found primarily as nodules and geodes in decomposed volcanic ash and basalt of [[Lopingian|Late Permian]] age. The largest deposits are in the Brazilian state of [[Rio Grande do Sul]], but significant amounts can also be found throughout southeastern [[Brazil]]. Some specimens can be very colorful and include features such as eyes, tubes, dendrites, and sagentite. However, most Brazilian agate that is mined is naturally pale yellow, gray, or colorless and artificially dyed before being brought to market.
* [[Condor agate|''Condor agates'']] are found in the [[Mendoza Province|Mendoza]] province of [[Argentina]]. They typically have bright red and yellow fortification banding and may contain mossy or sagenitic inclusions. Other varieties of agate can also be found in the [[Patagonia]] area of Argentina, including ''crater agate'' (typically hollow nodules with black and red bands) and ''puma agate'' (agatized coral). 
* [[Uruguay]] was the first major source of agates in South America. Agates were discovered there in 1830, but sources in neighboring Brazil became more popular in the late 19th and 20th centuries.
* Agates have also been found in [[Chile]] and [[Peru]].<ref name="pabian" />{{rp|pp=122–131}}

<gallery mode="packed" heights="130px">
Brazilian agate section (detail).JPG|Natural Brazilian agate
5agat, Brazylia.jpg|Dyed Brazilian agate
Argentina001.jpg|Condor agate
Achat 1.jpg|Agate from Uruguay
</gallery>