Jurassicz1 Posted September 14, 2020 Share Posted September 14, 2020 This is probably just something stupid but these black dots always come on my fossils really hard to remove them is it just matrix i had not seen? Its really annoying they always show up. Its on the side of the belemite. Link to comment Share on other sites More sharing options...
Ludwigia Posted September 14, 2020 Share Posted September 14, 2020 4 minutes ago, Jurassicz said: This is probably just something stupid but these black dots always come on my fossils really hard to remove them is it just matrix i had not seen? Its really annoying they always show up. Its on the side of the belemite. Do you mean this itty bitty dot? Is that so bad? Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Jurassicz1 Posted September 14, 2020 Author Share Posted September 14, 2020 37 minutes ago, Ludwigia said: Do you mean this itty bitty dot? Is that so bad? Well not so bad. But they come almost everytime i prep. Just wanted to know what they were and how to remove them:) Link to comment Share on other sites More sharing options...
FranzBernhard Posted September 14, 2020 Share Posted September 14, 2020 1 minute ago, Jurassicz said: But they come almost everytime i prep. ? What does this really mean? Are they below a layer you have already removed? Do the form after prep? Franz Bernhard Link to comment Share on other sites More sharing options...
Jurassicz1 Posted September 14, 2020 Author Share Posted September 14, 2020 1 hour ago, FranzBernhard said: ? What does this really mean? Are they below a layer you have already removed? Do the form after prep? Franz Bernhard I always notice them after prep and sometimes its easy to remove or super hard. Link to comment Share on other sites More sharing options...
snolly50 Posted September 14, 2020 Share Posted September 14, 2020 Are you using an air scribe? oil? Human beings, who are almost unique in having the ability to learn from the experience of others, also are remarkable for their apparent disinclination to do so. - Douglas Adams, Last Chance to See Link to comment Share on other sites More sharing options...
FranzBernhard Posted September 14, 2020 Share Posted September 14, 2020 Wild guess: Mn-oxide pustules formed in the separation layer ("crack") between fossil and matrix. That´s a really wild guess of me, but this is a rather common thing in some environments (formation of Mn-oxides in cracks). Franz Bernhard 1 Link to comment Share on other sites More sharing options...
digit Posted September 14, 2020 Share Posted September 14, 2020 I concur that most of the times I see black encrustations on fossils they turn out to be magnesium oxide. Usually, they are pretty porous and flaky and can be easily scraped/brushed clean. Sometimes they are more dense and resist simple mechanical removal. Can we see other examples on some of your other fossils? Cheers. -Ken Link to comment Share on other sites More sharing options...
Jurassicz1 Posted September 14, 2020 Author Share Posted September 14, 2020 44 minutes ago, snolly50 said: Are you using an air scribe? oil? No just dental picks Link to comment Share on other sites More sharing options...
Jurassicz1 Posted September 21, 2020 Author Share Posted September 21, 2020 On 9/14/2020 at 8:21 AM, digit said: I concur that most of the times I see black encrustations on fossils they turn out to be magnesium oxide. Usually, they are pretty porous and flaky and can be easily scraped/brushed clean. Sometimes they are more dense and resist simple mechanical removal. Can we see other examples on some of your other fossils? Cheers. -Ken Yes heres one its really annoying. :/ 1 Link to comment Share on other sites More sharing options...
digit Posted September 21, 2020 Share Posted September 21, 2020 You seem to have high expectations for your fossils. The fossil shown above looks nicely prepped and I don't find the tiny dark spots objectionable in any way. I find them like freckles or moles in people--simply part of the idiosyncratic nature of individuals. I'm curious as to what the button-like fossil shown is as I'm not familiar with it. Here's a vertebra I worked on last week at the vertebrate paleontology warehouse where I was gluing back together broken fossils and doing some light preparation work to remove adhering matrix. Though I neglected to take a post-cleaning photo, most of the magnesium oxide was powdery and came away with the sandy matrix. There were blackish areas at the surface of the bone when the matrix was gone but this does not detract from the scientific value of the specimen. Cheers. -Ken Link to comment Share on other sites More sharing options...
JohnJ Posted September 21, 2020 Share Posted September 21, 2020 3 hours ago, digit said: I'm curious as to what the button-like fossil shown is as I'm not familiar with it. Echinoid tubercle The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
digit Posted September 21, 2020 Share Posted September 21, 2020 38 minutes ago, JohnJ said: Echinoid tubercle Ah, makes sense. Disarticulated, it was a bit of a mystery. Cheers. -Ken Link to comment Share on other sites More sharing options...
Harry Pristis Posted September 21, 2020 Share Posted September 21, 2020 The chemical symbol Mn stands for manganese, not magnesium which has Mg for a symbol. I think that it is likely that these spots are manganese, which is widespread and known to stain fossils. 1 http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
Phevo Posted September 21, 2020 Share Posted September 21, 2020 These look like fossils from Ignaberga, if they were found on the surface they may have been exposed for a long time and what you are seeing could be growth. I have used a toothbrush that has been cut so the brushes are around 3mm in length to scrub the fossils from that site 1 Link to comment Share on other sites More sharing options...
digit Posted September 21, 2020 Share Posted September 21, 2020 2 hours ago, Harry Pristis said: The chemical symbol Mn stands for manganese, not magnesium which has Mg for a symbol. I think that it is likely that these spots are manganese, which is widespread and known to stain fossils. Whoops! Typo there--magnesium oxidizes very well from its metallic state (with a white hot flame in fact). The black spots are the commonly found manganese oxide which are familiar to anyone who has been to Sharktooth Hill as they are found on many of the shark teeth from there. Cheers. -Ken Link to comment Share on other sites More sharing options...
Jurassicz1 Posted September 22, 2020 Author Share Posted September 22, 2020 23 hours ago, digit said: You seem to have high expectations for your fossils. The fossil shown above looks nicely prepped and I don't find the tiny dark spots objectionable in any way. I find them like freckles or moles in people--simply part of the idiosyncratic nature of individuals. I'm curious as to what the button-like fossil shown is as I'm not familiar with it. Here's a vertebra I worked on last week at the vertebrate paleontology warehouse where I was gluing back together broken fossils and doing some light preparation work to remove adhering matrix. Though I neglected to take a post-cleaning photo, most of the magnesium oxide was powdery and came away with the sandy matrix. There were blackish areas at the surface of the bone when the matrix was gone but this does not detract from the scientific value of the specimen. Cheers. -Ken Ok thanks for telling me! Link to comment Share on other sites More sharing options...
Jurassicz1 Posted September 22, 2020 Author Share Posted September 22, 2020 15 hours ago, Phevo said: These look like fossils from Ignaberga, if they were found on the surface they may have been exposed for a long time and what you are seeing could be growth. I have used a toothbrush that has been cut so the brushes are around 3mm in length to scrub the fossils from that site Yes they are from ignaberga ok i will try that with a old toothbrush Link to comment Share on other sites More sharing options...
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