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
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
╳Discussions
💬 Home🔎 Search📅 LatestGroups
EducationOpen discussion area.Fakes & FraudsOpen discussion area.Field CollectingOpen discussion area.FossilsOpen discussion area.Gems and GemologyOpen discussion area.GeneralOpen discussion area.How to ContributeOpen discussion area.Identity HelpOpen discussion area.Improving Mindat.orgOpen discussion area.LocalitiesOpen discussion area.Lost and Stolen SpecimensOpen discussion area.MarketplaceOpen discussion area.MeteoritesOpen discussion area.Mindat ProductsOpen discussion area.Mineral ExchangesOpen discussion area.Mineral PhotographyOpen discussion area.Mineral ShowsOpen discussion area.Mineralogical ClassificationOpen discussion area.Mineralogy CourseOpen discussion area.MineralsOpen discussion area.Minerals and MuseumsOpen discussion area.PhotosOpen discussion area.Techniques for CollectorsOpen discussion area.The Rock H. Currier Digital LibraryOpen discussion area.UV MineralsOpen discussion area.Recent Images in Discussions
Identity HelpIs This Prehnite and Calcite or Hemimorphite or Something Else?
17th Apr 2018 02:19 UTCDeanna Kane
I know I've been probably annoying all of you lately with all my requests for identifications, but hopefully you guys aren't too sick of me yet, LOL
I just got this big, heavy 6 inch by 6 inch specimen. The person I bought it from is not a mineral collector and was just selling it for $3 so I had to have it for that awesome price. It had a very old yellowed label on it that said Phrenite or Hemimorphite with calcite.
I know many of you advance collectors are groaning and rolling your eyes by now. Inside your heads you are shouting, "stop collecting pieces that aren't labeled with location or identification", but like I said earlier for $3, I couldn't resist because it was pretty.
Any ideas what the heck this could be?
More pictures to follow...
Sorry in advance, but this post is picture heavy, LOL
17th Apr 2018 02:37 UTCAlfredo Petrov Manager
17th Apr 2018 02:40 UTCDeanna Kane
17th Apr 2018 02:56 UTCErin Delventhal Manager
Completely off topic to your question here, but as some advice to a burgeoning collector, I'd recommend that you consider investing in an ultrasonic machine, which is a very effective and mineral-friendly way of cleaning your specimens.
17th Apr 2018 03:07 UTCDeanna Kane
17th Apr 2018 03:09 UTCDeanna Kane
17th Apr 2018 03:16 UTCDeanna Kane
17th Apr 2018 03:27 UTCDeanna Kane
I just put my spotlight on it and got my jeweler's loop out. I really think what looks like dirt is definitely a mineral.
The best I can describe it is it reminds me of a toy I had as a child. It was a picture of a bald guy encased in plastic with iron/metallic particles and you took a magnet and moved them around to give the bald guy hair, a beard and a mustache. It looks like those little magnetic particles up close. Sorry if my analogy was ridiculous, but this is all I can think of right now to describe it, lol.
17th Apr 2018 03:46 UTCAlfredo Petrov Manager
Weaker acid is better, because if it's too strong, or you leave it in too long, it will hurt the luster of the prehnite and zeolites. A better method might be to just leave as is and enjoy the contrast the black spots give it. ;))
17th Apr 2018 04:13 UTCErin Delventhal Manager
However, I'm not insisting that the black material needs to be removed, especially if it's mineralized - though Alfredo's suggestion as to how to do so is fair, as is the suggestion of just enjoying it as it is.
Outside of all of that, I still think you'd benefit from having an ultrasonic.
17th Apr 2018 04:15 UTCA. M.
17th Apr 2018 04:19 UTCDeanna Kane
17th Apr 2018 06:10 UTCDeanna Kane
I appreciate that information very much : )
17th Apr 2018 14:36 UTCAlfred L. Ostrander
Just be careful with an ultrasonic cleaner. Fragile specimens can end up as a pile of debris at the bottom of the tank.
17th Apr 2018 15:25 UTCErin Delventhal Manager
Would those fragile specimens be better off subjected to a toothbrush?
I've had no issues with delicate specimens in my ultrasonic, so I'm curious what you're referring to.
Erin
17th Apr 2018 16:14 UTCDonald B Peck Expert
I think A. Mathouser nailed it. The small lath like xls that are scattered over the green prehnite look to be laumontite. Possibly from the Paterson, NJ area (it is typical}.
Don
17th Apr 2018 19:27 UTCAlfred L. Ostrander
Can't say I'm too hot on starting out by scrubbing away with a toothbrush either. Maybe someday you will find out what I mean when you find a bit of debris at the bottom of your ultrasonic tank as the result of putting the wrong thing in an ultrasonic. I can say the same thing about cleaning certain minerals with high pressure sprays. Works for some things, highly destructive for others.
Solubility is important. Friability is major. Porous matrix needs considered. Type of matrix needs to be considered.
Keep in mind that an ultrasonic is vibrating a bit vigorously. Sometimes too much for specimens. Even an insoluble crystal can be vibrated off the matrix.
Just forty some years of experience speaking here.
17th Apr 2018 23:22 UTCGregg Little 🌟
I thought laumontite was susceptible to dehydration and ending up as a crumbing mess in the specimen tray. Also, if we are talking about the same fine acicular crystals, they appear to have a semi-transparent look to them. All the laumonite in my collection has crumbed and is not in the least translucent. I also can't consistently see any of those obvious "chisel-like" terminations. Am I missing something? I don't really have any other suggestions other than may be heulandite?
18th Apr 2018 01:26 UTCDonald B Peck Expert
18th Apr 2018 02:21 UTCA. M.
26th Apr 2018 03:17 UTCStephen C. Blyskal Expert
26th Apr 2018 07:43 UTCGlen Gruber (2)
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: March 29, 2024 15:41:55
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: March 29, 2024 15:41:55