IMPORTANT MESSAGE. We need your support now to keep mindat.org running. Click here to find out why.
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 Articles
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 CompaniesStatisticsThe ElementsUsersBooks & MagazinesMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery
bannerbannerbannerbannerbannerbanner

General

For general comments about the site 

Are you sure you want to report this post?

You may optionally give an explanation for why this post was reported, which will be sent to the moderators along with the report. This can help the moderator to understand why you reported the post.



 

Re: a simple explaination of agate formation

Posted by: Donald Kasper

Very good. The southern Brazil/Paraguay region is full of big amygdules, I must be wrong and you proved it. How old are these lavas? Cretacecous. Okay, where was South America in Cretaceceous? Farther south in a desert belt. Okay, what is the brown staining? Humic acid leaching from being moved up to the equator where plant matter in groundwater stained them. Now you know.

Would you like for me to tell you where Germany was in Permian? Okay, if the shells of geodes are kaolinized and the agates are full of kaolinite, those are 300-400 million year old agates and that was weathering.



bannerbannerbannerbannerbannerbanner
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2018, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: November 19, 2018 11:34:59
Go to top of page