Chris Parson Posted March 1, 2022 Report Share Posted March 1, 2022 As I was sorting through my mineral collection a couple of weeks ago, I came to think of a Veiligglass marble of mine that is said to contain green aventurine. That made me question how many companies deliberately used minerals in their marbles. I have noticed that companies like Akro, Christensen and Vitro also had "Agate" in their company name. What do you people know? Link to comment Share on other sites More sharing options...
Ric Posted March 1, 2022 Report Share Posted March 1, 2022 That's a pretty marble, Chris. I think that the word "agate" was initially adopted by American marble companies since it was associated with the quality stone marbles from Germany, which were something they wanted to replicate with glass. As for minerals in marbles, gold lutz and mica were used in early German handmades many years ago. I think aventurine is sometimes purposefully produced and sometimes just results from reactions of certain colorants used in he manufacturing process. I am sure others could add more to this discussion. Link to comment Share on other sites More sharing options...
Steph Posted March 1, 2022 Report Share Posted March 1, 2022 Glass companies definitely deliberately used the names of stones to try to make glass marbles sound more like children's beloved stone marbles. In 1930 in America, a lawsuit was filed with the government by the onyx industry to force some glass companies to stop calling their products "onyx". The suit was successful. Akro still used the name onyx for awhile after that. Not sure why they got away with it, but they didn't keep doing it for long. The stone aventurine was named after the glass aventurine -- did you know that? Aventurine glass was discovered and named in the 1700's. 1 Link to comment Share on other sites More sharing options...
Alan Posted March 1, 2022 Report Share Posted March 1, 2022 Like several other words used in the hobby, "aventurine" is misused and abused. "Aventurine" is a mineral - a form of quartz. The reflective flakes in glass marbles are NOT aventurine, despite how people have come to dream of it as a rare substance. Those flakes are excess colorant or chemical precipitate from chemical reactions. 2 Link to comment Share on other sites More sharing options...
Chris Parson Posted March 1, 2022 Author Report Share Posted March 1, 2022 Thank you for your input @Ric, @Steph and @Alan! I don’t know if it’s even possible to mix, for example, quartz with glass? Some types of quatz also tend to shift colour when exposed to heat. A mineral like citrine also contain iron which may or may not react in a certain way when expised to the hot glass mass…? But I’m just speculating here and my brain is partially disconnected after 9 pm. Link to comment Share on other sites More sharing options...
Da Roberto Posted March 1, 2022 Report Share Posted March 1, 2022 However, sometimes, some notice tiny inclusions in the green and mistake it for aventurine, but it's actually just undissolved dye. If your glistens in the light or the sun, it's av, otherwise it's just (as I said) undissolved dye Link to comment Share on other sites More sharing options...
Alan Posted March 1, 2022 Report Share Posted March 1, 2022 1 hour ago, Chris Parson said: Thank you for your input @Ric, @Steph and @Alan! I don’t know if it’s even possible to mix, for example, quartz with glass? Some types of quatz also tend to shift colour when exposed to heat. A mineral like citrine also contain iron which may or may not react in a certain way when expised to the hot glass mass…? But I’m just speculating here and my brain is partially disconnected after 9 pm. Quartz and glass have different melting points, and therefore different coefficients of expansion (COE). (Yes - you can make a "glass" from quartz). Attempts to mix the mineral quartz with glass (two fairly different melting points) will result in internal stresses as the glass cooled. Those internal stresses are what cause annealing fractures. Link to comment Share on other sites More sharing options...
akroorka Posted March 1, 2022 Report Share Posted March 1, 2022 I appreciate all that has been said. (good to see you back Chris) This type of sparkle/defect, whatever you may call it, will routinely show up in a green colored part of many makers and their marbles. We in the marble collecting world will more than likely refer to it as AV for many years into the future. Right or wrong, it is just the nature of this beast we are all involved with. Why does the green color carry this pollution/desirable defect, more than any other color is my question? Thanks all and--- Marble On!! Link to comment Share on other sites More sharing options...
Ric Posted March 1, 2022 Report Share Posted March 1, 2022 7 hours ago, Steph said: The stone aventurine was named after the glass aventurine -- did you know that? Aventurine glass was discovered and named in the 1700's. 41 minutes ago, akroorka said: We in the marble collecting world will more than likely refer to it as AV for many years into the future. Right or wrong, it is just the nature of this beast . . . I found what Steph said very interesting - maybe the geologists are the ones who need to call it something else. I mean, the mineral is not glass, right? 2 Link to comment Share on other sites More sharing options...
wvrons Posted March 2, 2022 Report Share Posted March 2, 2022 The marble looks like a Jabo . Maybe different views would change that ? Anyone else seen any Veiligglas with this much aventurine ? I don't think I have had or seen any Veiligglas with av ? Aventurine - Websters= Glass containing opaque sparkling particles of foreign material usu. copper or chromic oxide. A translucent quartz spangled throughout with scales of mica or other material. Link to comment Share on other sites More sharing options...
akroorka Posted March 2, 2022 Report Share Posted March 2, 2022 I think that it a Veli Ron. All makers are blessed once in awhile with this green sparkly stuff. I still do not know why--something in the green glass recipe no doubt. The other side would tell the tale for sure. Marble--On!! 1 Link to comment Share on other sites More sharing options...
Chris Parson Posted March 2, 2022 Author Report Share Posted March 2, 2022 8 hours ago, Alan said: Quartz and glass have different melting points, and therefore different coefficients of expansion (COE). (Yes - you can make a "glass" from quartz). Attempts to mix the mineral quartz with glass (two fairly different melting points) will result in internal stresses as the glass cooled. Those internal stresses are what cause annealing fractures. Yes, melting points! 👍🏼👍🏼👍🏼 That was what I was reaching for but never got to. Thank you! Link to comment Share on other sites More sharing options...
Chris Parson Posted March 2, 2022 Author Report Share Posted March 2, 2022 7 hours ago, akroorka said: I appreciate all that has been said. (good to see you back Chris) This type of sparkle/defect, whatever you may call it, will routinely show up in a green colored part of many makers and their marbles. We in the marble collecting world will more than likely refer to it as AV for many years into the future. Right or wrong, it is just the nature of this beast we are all involved with. Why does the green color carry this pollution/desirable defect, more than any other color is my question? Thanks all and--- Marble On!! Yes, this this is very informative. Knowledge and ideas being shared. (Good to see you too) You refer to the colour as AV, as in AVenturine? Link to comment Share on other sites More sharing options...
Chris Parson Posted March 2, 2022 Author Report Share Posted March 2, 2022 5 hours ago, wvrons said: The marble looks like a Jabo . Maybe different views would change that ? Anyone else seen any Veiligglas with this much aventurine ? I don't think I have had or seen any Veiligglas with av ? I don’t think I would be able to identify it myself but I got it from Joep and he says that it’s Veiligglass. Link to comment Share on other sites More sharing options...
Chad G. Posted March 2, 2022 Report Share Posted March 2, 2022 I think it's Veiligglas also, could you take a pic of the other side to confirm Chris, & a size also ?? Link to comment Share on other sites More sharing options...
Chris Parson Posted March 2, 2022 Author Report Share Posted March 2, 2022 4 hours ago, Chad G. said: I think it's Veiligglas also, could you take a pic of the other side to confirm Chris, & a size also ?? Sure! It’s 17 mm in diameter. Link to comment Share on other sites More sharing options...
Chris Parson Posted March 2, 2022 Author Report Share Posted March 2, 2022 And while we are messing about with the minerals; This is a 15 mm ball of pure bronzite. 1 Link to comment Share on other sites More sharing options...
Roberto Posted March 2, 2022 Report Share Posted March 2, 2022 11 minutes ago, Chris Parson said: Sicuro! Ha un diametro di 17 mm. Veiligglas, and one of the beautiful ones! Link to comment Share on other sites More sharing options...
wvrons Posted March 2, 2022 Report Share Posted March 2, 2022 I agree and with that much aventurine, it is a rare one. Link to comment Share on other sites More sharing options...
Ric Posted March 2, 2022 Report Share Posted March 2, 2022 6 hours ago, Chris Parson said: And while we are messing about with the minerals; This is a 15 mm ball of pure bronzite. That's a nice looking stone, Chris. Link to comment Share on other sites More sharing options...
Chad G. Posted March 2, 2022 Report Share Posted March 2, 2022 "Thanks Chris" yes, I see Veiligglas in the OP Link to comment Share on other sites More sharing options...
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