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WikiProject Gemology and Jewelry / Gemstones  (Rated Start-class, Low-importance)
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WikiProject Geology (Rated Start-class, Low-importance)
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Deleted advertising[edit]

Advertizing deleted. Wikipedia is not for free advertizing. Vsmith 02:45, 9 Feb 2005 (UTC)

Etymology Section[edit]

the Greek word χαλκεδονιος is found more than once. See, e.g., the Acts of Thomas 108. (talk) 18:08, 5 April 2011 (UTC)

Also the Bauer-Danker lexicon (p. 1076) says that Pliny (NH 37, 7, 92ff) calls Jasper and a "certain kind of emerald" Chalcedonian Ll1324 (talk) 20:56, 14 May 2014 (UTC)

Needs more information about etymology - it gives the Latin word chalcedonius but not what that means! I always assumed it was named after the city of Chalcedon but maybe not.Gymnophoria (talk) 13:34, 21 September 2014 (UTC)

Varieties Section[edit]

I have created a "Varieties" section which systematically considers each variety in turn. It still needs a lot of work (to add a fuller description of each variety), and I will improve on it later. (I have also moved some content into a "History" section.) Hyperdeath (talk) 12:50, 21 March 2008 (UTC)

'Blood Stone'[edit]

"Plasma is a bright to emerald-green chalcedony that is sometimes found with small spots of jasper resembling blood drops; it has been referred to as blood stone or heliotrope."

Is it possible that the link to haematite (also sometimes known as 'blood stone') is incorrect? As far as I'm aware, haematite does not fit the description of a 'bright to emerald-green chalcedony'.

Done - missed that before, thanks, Vsmith 02:51, 3 January 2006 (UTC)


Sorry about the posting. I don't know the etiquette of adding things to pre-existing pages. But I'd like to add some basic applied geochemistry to this page if thats possible. Cheers.

Composition of Chalcedony[edit]

The article provides an outdated theory as to chalcedony's composition, namely that it's a form of quartz. It is now known to contain moganite: Hyperdeath 18:00, 27 April 2007 (UTC) (time approximate -- forgot to add signature)

Added a reference for the moganite info. Rickert 03:38, 28 April 2007 (UTC)

I have edited the geochemistry section to reflect the fact that chalcedony and quartz are not crystallographically identical. Hyperdeath 11:37, 29 April 2007 (UTC)


I have cleaned up the varieties section slightly. Hyperdeath 11:37, 29 April 2007 (UTC)


I have tagged Aventurine with a merge to Chalcedony tag. All of the information in the Aventurine article is unreferenced and much duplicates the information that is here. --Kevmin (talk) 02:46, 6 October 2009 (UTC)

Gem-fanat (talk) 19:38, 22 December 2009 (UTC)

I have been bold and undone the merge. I agree with the concerns raised about the article, but dumping the content here is not the answer. It is just too long to fit into what is essentially an index to variety sub-articles. It disrupts the flow of the article. If anyone strongly objects to this, I would be happy to help improve the aventurine article.— Hyperdeath(Talk) 20:45, 7 April 2011 (UTC)

Aventurine is not a variety of Chalcedony[edit]

It should not appear on this page. Chalcedony is a microcrystalline quartz whereas aventurine is a crystalline quartz with small inclusions of other materials. I have consulted the "Glossary of Geology" and the "Dictionary of Gems and Gemology" to confirm this. — Preceding unsigned comment added by (talk) 20:59, 7 September 2012 (UTC)

Possible conflict of facts?[edit]

Hey, I just wanted to point out that in the intro block of this page, the following statement occurs: "according to the OED a connection with the town of Chalcedon in Asia Minor is 'very doubtful'". Then, later on under "History" it reads, "The term chalcedony is derived from the name of the ancient Greek town Chalkedon in Asia Minor, in modern English usually spelled Chalcedon...". The latter statement has no citation; it might be worth finding one, and rewording things to point out this conflict in opinion Opensourcejunkie (talk) 18:52, 17 December 2012 (UTC)

Artificial "cats eye?"[edit]

I notice a header about imitations? I saw this "synthetic" bracelet at
Model Number: SHSB-034, Gemstone Type: Mineral Gemstones, Gemstone Material: Chalcedony, Treatments Applied: Other, Optical Special Effects: Pleochroic/Pleochroism, material: cat eyes stone.
There are many variations nearby. Photos look like tiger eye.
-- (talk) 23:07, 23 March 2013 (UTC)Doug Bashford

Pliny vs Revelations?[edit]

Just to remark that the Intro section implicitly dates Pliny's work prior to the book of Revelations. "Natural History" is confidently dated about 78AD but Revelations is hard to date. It seems to me that the latest authoritative dating is J.A.T Robinson's "Redating the New Testament" (1976), and he dates Revelations c.61AD. Thus Revelations was prior to Pliny. I have adjusted to wording to reflect this. C.jeynes (talk) 16:36, 11 July 2014 (UTC)

Hapax Legomenon[edit]

I never heard the term "hapax legomenon," and found the sentence distracting and confusing. I would have preferred to remove it in my latest revision [02:53, 30 June 2016‎] But I only clarified the sentence, deferring to the judgment of a more experienced contributor. Just because there is a formal term for what one is describing does not mean it needs to be introduced, to create a teaching moment. In summary: "found nowhere else" is educational but I don't think the Greek term itself adds to the value of the page and should be removed. — Preceding unsigned comment added by Cab.jones (talkcontribs)