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:
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

Platy mineral from Franklin, NJ

Posted by Harold Moritz  
Harold Moritz April 01, 2019 07:31PM
This is a platy mineral on calcite/andradite/pyroxene/wollastonite rock from Franklin, collected by Roy Epting, Sr. circa 1930s-1950s. It does not fluoresce (it looks dark red from a little bit of underlying calcite color coming through), appears to have one or more very god cleavages and a carefully measured hardness of 5.5. My first thought was barite, but no fluorescence, and have never seen it in plates this large, or wollastonite, but that mineral is in there already as separate yellow-fluorescing grains. So, getting to the rarities, possibly barylite or barysilite, but they have hardnesses of 7 and 3, respectively. Barylite has weak blue fluorescence (with today's lamps), which I have photographed at Harvard, so that leaves barysilite, which has none. Dont have much experience with these, so throwing it out to the Franklin collecting community for help. 7 x 6 x 4.5 cm 265g

Edited 1 time(s). Last edit at 04/01/2019 07:33PM by Harold Moritz.
James Van Fleet April 15, 2019 02:22PM
I think you are going to find that this is bustamite -- possibly ferrobustamite! I'm very interested in any test results, I have been planning to write this assemblage up for the Picking Table. Found with "third find" wollastonite specimens, about 30% of the specimens I have handled. And it does in fact fluoresce a very dark, weak red.
Harold Moritz April 15, 2019 03:14PM
My initial impression was that it does have a very weak red fluorescence, but with the calcite glow as a backdrop I was uncertain. I would never have pegged bustamite as a potential identification, and after reading Dunn I still would not (he makes no mention of a ferrobustamite, either). If it is bustamite then it is an under-reported occurrence. Only piece we found in the collection like this, though in hindsight you might find more. And it would be nice to know I can measure hardness properly cuz bustamite's is reported here on mindat as H=5.5-6.5. A bit has gone out for SEM-EDS analysis.
Sorry, only registered users may post in this forum.

Click here to login

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: April 21, 2019 01:24:01
Go to top of page