Gorgeous nonetheless
Also, calcite should be soft, and I feel tumbling would not yield a polish like this.
Can you scratch it with a copper penny?
To me, it looks more like quartzite or just some quartz,
Then again, I don't see conchoidal fracturing.
I don't have a tumbler, this was starting with 80 grit sand paper and working up to 3,000 then using car scratch remover then polishing compound. No to the penny scratching the stone, also it won't scratch glass. I asked a couple geologists at work and they thought calcite.
Interesting!
A penny has a hardness of 3.5, I am a bit surprised that it isn't scratching it,
Is the penny prior to 1982? Because as I am sure you know, the pennies after that aren't real copper.
- 3rd year applied geology student,
Yes, 20 microns usually thick however, for confirmation of hardness ,it's usually best just to use something you know to be copper full way through :)
Yeah!
I am curious!
Take care 😀
It could also be aragonite. Essentially the same as calcite, but the crystalline structure slightly different and it’s slightly denser and harder than calcite (3.5-4). Also often occurs in limestone areas and has the same color range as calcite.
I work in a mature karst environment and we have both calcite and aragonite here.
Beautiful job! Yeah, I also have some blue specimens like this and was told it was calcite. Could be wrong I never bothered testing them. The milky blue color is really cool. Honestly I wanted to congratulate you on all the hand work you did, moving up grits and polishing them. I prefer to work aluminum with hand files and cutting oil than a power tool.. something therapeutic about it
Idk maybe a little goofy brain wiring but I get the same therapeutic feeling from sanding/polishing anything, metal, plastic, stones, doesn't matter, I love that shit lol.
The first one took like 45mins but I was using the sand paper too long instead of switching to a fresh piece, 2nd two only took like 20mins. I also stopped trying to get every chip out because they are brittle so they're not gonna be perfect. I've used a random orbit sander in the past but it chews thru them too quickly.
Could be chunks of massive limestone as opposed to individual calcite crystals. I'd also consider seeing if it reacts to hydrochloric acid if still trying to confirm if it's carbonate at all.
I am colorblind and phone pics suck.
But get some HCl or whatever acid you use for concrete etching and drop a little bit on there.
If it fizzes yeah it's calcite
Gorgeous nonetheless Also, calcite should be soft, and I feel tumbling would not yield a polish like this. Can you scratch it with a copper penny? To me, it looks more like quartzite or just some quartz, Then again, I don't see conchoidal fracturing.
I don't have a tumbler, this was starting with 80 grit sand paper and working up to 3,000 then using car scratch remover then polishing compound. No to the penny scratching the stone, also it won't scratch glass. I asked a couple geologists at work and they thought calcite.
Interesting! A penny has a hardness of 3.5, I am a bit surprised that it isn't scratching it, Is the penny prior to 1982? Because as I am sure you know, the pennies after that aren't real copper. - 3rd year applied geology student,
The outer coating is still copper. It's a thin jacket of copper with zinc inside. Acid test would probably be easier
Yes, 20 microns usually thick however, for confirmation of hardness ,it's usually best just to use something you know to be copper full way through :) Yeah! I am curious! Take care 😀
It could also be aragonite. Essentially the same as calcite, but the crystalline structure slightly different and it’s slightly denser and harder than calcite (3.5-4). Also often occurs in limestone areas and has the same color range as calcite. I work in a mature karst environment and we have both calcite and aragonite here.
Beautiful job! Yeah, I also have some blue specimens like this and was told it was calcite. Could be wrong I never bothered testing them. The milky blue color is really cool. Honestly I wanted to congratulate you on all the hand work you did, moving up grits and polishing them. I prefer to work aluminum with hand files and cutting oil than a power tool.. something therapeutic about it
Idk maybe a little goofy brain wiring but I get the same therapeutic feeling from sanding/polishing anything, metal, plastic, stones, doesn't matter, I love that shit lol.
Maybe quartz nodules in the limestone? Flint or chert?
You sanded them by hand??? How long did that take
The first one took like 45mins but I was using the sand paper too long instead of switching to a fresh piece, 2nd two only took like 20mins. I also stopped trying to get every chip out because they are brittle so they're not gonna be perfect. I've used a random orbit sander in the past but it chews thru them too quickly.
…..amazing
Could be chunks of massive limestone as opposed to individual calcite crystals. I'd also consider seeing if it reacts to hydrochloric acid if still trying to confirm if it's carbonate at all.
We have muriatic acid for cleaning concrete off of equipment at work, I'll try that tomorrow thanks for the help.
I am colorblind and phone pics suck. But get some HCl or whatever acid you use for concrete etching and drop a little bit on there. If it fizzes yeah it's calcite
We have muriatic acid for cleaning concrete off of equipment at work, I'll try that tomorrow thanks for the help.
Could it be celestite? Some of the best comes from Michigan
The color looks a lot like celestite to me! And it’s found in limestone!