SUPPORT US. If mindat.org is important to you, click here to donate to our Fall 2019 fundraiser!
Log InRegister
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsBooks & Magazines
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryMineral Photography

Identity HelpColor changing Rock, but what kind of?

16th Sep 2019 15:26 BSTRubel Shahab

04248320015686438482346.jpg
This rock is bluish black in indoor light but once taken to the window light it changes color to vivid orange/ golden. The changed color shown in the reply.

16th Sep 2019 15:28 BSTRubel Shahab

04088640015686440492558.jpg
Normal day afternoon light from my window.

17th Sep 2019 01:39 BSTIan Nicastro

It appears to be Chalcedony or Agate. Although your first photo isn't bright enough to illustrate the blue, I know what you are talking about, and the 'color change' you see is due to this:

17th Sep 2019 01:38 BSTKevin Conroy Expert

Possibly chalcedony.   What is its hardness, and does it fluoresce?

17th Sep 2019 01:56 BSTPaul Brandes Manager

I would tend to say chalcedony as well.
 
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Public Relations by Blytheweigh.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2019, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: October 16, 2019 10:23:12
Go to top of page