Log InRegister
Quick Links : The Mindat ManualThe Rock H. Currier Digital LibraryMindat Newsletter [Free Download]
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 ElementsThe Rock H. Currier Digital LibraryGeologic Time
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 MuseumsClubs & OrganizationsMineral Shows & EventsThe Mindat DirectoryDevice SettingsThe Mineral Quiz
Photo SearchPhoto GalleriesSearch by ColorNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

Identity HelpRadial Star-like Crystal in Matrix

19th May 2017 02:51 UTCRobert Darabos

07214660016060179842288.jpg
Radial, star-like crystal found on an unknown host rock.

Guatemalan Highlands. Huehuetenango.

I've seen these very rarely and had just assumed they were organic, but these pictures (to me) look like crystal formations.

Any guesses?

Carbonate filling in a cavity from old organic matter, perhaps?

Or a different mineral altogether?





01784320015652908992793.jpg


08576020015652908992480.jpg

19th May 2017 09:04 UTCErik Vercammen Expert

It may be a secondary mineral (in that case, probably a fosfate) that grew in a crack of the stone; compare with this structure https://www.mindat.org/photo-3656.html

19th May 2017 17:33 UTCDonald B Peck Expert

Robert, The radiating crystals could be any number of secondary minerals, crystallized in a joint crack. Erik has suggested a phophate . . . one way to check that is to drop some warm HCl (moderate concentration) on one of them. If it is a phosphate, it should dissolve. Alfredo has suggested strontianite, which will also dissolve in HCl. Try hitting the spot treated with HCl with the flame from a gas torch. If you get a scarlet flash, strontium is present. Might work with vinegar instead of HCl, I am not sure.
 
Mineral and/or Locality  
Mindat Discussions Facebook Logo Instagram Logo Discord Logo
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 1993-2024, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: April 25, 2024 05:52:39
Go to top of page