Post subject: Overwhelmed with info, please help identify!
Posted: Wed Sep 09, 2020 12:36 pm
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Joined: Tue Sep 08, 2020 1:39 pm Posts: 14
Can anyone help identify? I’m new to this this and am trying to identify a stone for the first time. For three days I feel like a I’ve researched and only gone deeper into a black hole of information! From my understanding on how to identify a rock, these are the characteristics of my stone.
Found in a Texas river along a pooled area with other river rocks Blackish green in color Opaque upon initial inspection but translucent with back light The small side of it is glassy, vitreous? And the other side looks greasy? Hardness- fingernail- pass, copper 1961 coin- pass, nail- pass, glass-pass, masonry bit- fail so 7-8.5? Pics below. Thank you your time in any help you can provide!
Attachments:
File comment: Greasy side dry 0E16499B-154A-4B89-B813-564401B13740.jpeg [ 2.04 MiB | Viewed 2208 times ]
File comment: “Greasy” side when wet in daylight 6B0171E0-DCF2-42EA-888E-8F227267779E.jpeg [ 2.71 MiB | Viewed 2208 times ]
Post subject: Re: Overwhelmed with info, please help identify!
Posted: Wed Sep 09, 2020 2:59 pm
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Joined: Thu May 12, 2016 2:18 am Posts: 1542
Most likely glass. Glass is commonly found in rivers, on beaches, and mixed with other natural stones almost anywhere.
If the glass is the result of industrial waste it is called slag.
If is natural glass from Volcanism it is called obsidian.
However as far as I know there are no Obsidian deposits in Texas.
The sharp nature of the specimen indicates that although found in a river environment, it has not traveled far. If it had it would have a more rounded shape to it. This is another indication that it is glass, and you found it near where it was dropped.
Of course, any conclusion drawn from a picture on the web is just one step above a wild guess.
Post subject: Re: Overwhelmed with info, please help identify!
Posted: Wed Sep 09, 2020 5:51 pm
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Joined: Tue Apr 05, 2016 7:58 pm Posts: 1424 Location: San Marcos, CA
I do not think a masonry bit scratch test would automatically designate it a 7.5-8 in hardness. It can still be glass even if the bit was just slightly harder than the subject being tested.
Post subject: Re: Overwhelmed with info, please help identify!
Posted: Fri Sep 11, 2020 1:53 am
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Joined: Tue Sep 08, 2020 1:39 pm Posts: 14
In rereading my replies I feel like I need to clarify something because I do not want anyone that took the time to respond to me to think I am ungrateful for your insight. Before posting I tried to find an answer in reading others posts on this forum. I also read the “please read this before you post” where I understood that supplying as much information as possible would get you a better chance at identifying your rock.. I supplied as much info as I couldn’t but didn’t have the means to weigh it so when I was told it was glass and I said it felt heavier than glass but I’m only a novice, I meant it in a way of adding to its description and hopefully a continuing in an informative conversation. I didn’t know mean to come across as arguing that it couldn’t be glass. I also supplied the table I used to conclude it’s hardness so if there was another means I should be using, maybe someone could guide me to a better reference.
I have posted about my item in two different groups and gotten 3 different responses from 4 different people. The other group I posted to is a group that collects rocks and minerals from Texas. It is a large group with varied experience but many with a lot of local experience. With two different opinions from that group I thought I’d try other places and hopefully at least get a general consensus. I don’t sell rocks or gems or what not. I’m just the kid that picked up cool rocks and never grew up in that aspect. I honestly don’t care if it’s glass or a piece of petrified plastic (making a funny ha,ha). I just collect these things because I like them. This was my first attempt at identifying any I’ve ever picked up and I hope for the sake of future rock collectors that will be make the choice to destroy our planet or see the beauty in it and appreciate it, that they are able to come to a place where the experts encourage their curiosity and support their inquires. I sincerely apologize if I came across as argumentative in my replies. I assure you I was not and in fact thought by stating that I am the novice, I was acknowledging others experience. I was really excited to learn more about the rocks in my bucket but after getting my hand slapped, I may just let them go onto my shelf. Barbara, with all due respect to you, I hope you decide to adjust your approach to be more welcoming and encouraging to anyone interested in this subject. I mean that in the kindest way, I wanted to be here, to learn, and share my knowledge with my son on our weekend road trips and his emptied pockets. I hope your passion for geology allows you to pass that on without criticism so people like me can do that.
I actually believe you were treated fairly and honestly.
Your unknown was identified.
Other platforms, the welcoming ones (cough cough) are often trying to sell you something. Not here.
Our long time members are all established industry professionals. There is nothing to gain by guessing or puffing or trying to entice you into taking the courses we offer.
If we know what something is, we'll tell you.
If we don't know we won't speculate, but we will always supply links to help you determine what you are trying to learn.
Post subject: Re: Overwhelmed with info, please help identify!
Posted: Fri Sep 11, 2020 7:35 pm
Gold Member
Joined: Tue Apr 05, 2016 7:58 pm Posts: 1424 Location: San Marcos, CA
I'm guessing here that based on the greasy and other descriptive terms on the images someone probably said jade. The flat slab appearance of it is kind of suspicious, maybe an 1850's gold miner returning from the California gold rush dropped a piece of slabbed jade out of their saddle bag or wagon while traveling through Texas. Been laying there for over hundred years of sand running over it. But the same answer comes to mind, its not worth the costs to take it and get properly identified. I would like to hear as well.
Post subject: Re: Overwhelmed with info, please help identify!
Posted: Fri Sep 11, 2020 11:25 pm
Gold Member
Joined: Thu May 12, 2016 2:18 am Posts: 1542
Rhobint wrote:
I’ve gotten a few more responses since:
Obsidian Obsidian with trace elements Glass Moldavite Basanite with Dunite
Seems the black hole just keeps getting deeper! Opinions heaviest toward obsidian and glass.
I will try to add the video I took today to this post. Not sure if it will allow be to attach something that size
I will go through the listed choices one by one for you.
"Obsidian" is a natural glass that only comes from erupting volcanoes, or flood basalt lava flows Since these structures are not known to exists in Texas the sample would have had to travel a great distance in the river you found it in. The lack of durability of obsidian makes survival of Obsidian over this distance and time highly unlikely. The angular form of you unknown pretty much completely eliminates this as a possibility.
"Obsidian with trace elements". Still Obsidian so same rules apply. Not likely.
"Glass" found everywhere. It is basically discarded trash. Very common to be found in the location, and in the condition of your sample. The most likely identification.
"Moldavite" is another form of glass but this time created by meteorite impact. These are a sub class of tektites. They are traditionally associated with Eastern European locations, but have been found in Africa and other places. I am not aware of any deposits in Texas. As we have previously discussed you sample has not traveled naturally to where you found it. Moldavite is usually easily identified visually by elongated bubbles, flow lines, and a distinctive "roiled" effect. This combination of features is not present in your sample. Moldavite before cutting and polishing has a distinctive look and texture in its natural state. It looks nothing like your sample. It is almost assuredly not a Moldavite.
"Basanite with Dunite" is an ultramafic (iron rich) igneous plutonic rock that is rarely found in continental areas and then only as a result of sub continental collisions. sometimes expelled from volcanoes as lava bombs. It is found in the Southwestern United States. However, I have never seen a sample that looks like yours. They are normally very course and the two minerals are more segregated. Still it is possible, but not likely.
You will notice that the most common theme running through the various guesses (which is all they are at this point) is that they are all some form glass. It seems people are trying to fit glass into the environment you found it in and so are suggest forms of naturally occurring glass. However, these natural occurring glasses don't fit with the geology or petrological history of your location. Far more likely is that man made glass fragment that found it's way there the same way you and your son found your way there.
Commenting in this thread are no less than 3 dual degreed geologist and gemologist. This is a fairly rare set of degrees to find in the World. I don't think a more accurate identification is possible without an in lab examination and testing by a trained professional.
I recognise that it is fun to think you found something unique or of value. But what you have is almost certainly worthless glass.
Sorry.
Last edited by 1bwana1 on Fri Sep 11, 2020 11:31 pm, edited 1 time in total.
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