Thread: I have a natural hone that even rgdominguez doesn't have! It's cobalt blue !!

A friend of mine called me today to look at a bunch of coral he had to see if it could be sold online.

While i was digging through the pile of coral/ rocks/seashells and such he told me that I could have whatever I wanted.

I came across this and my heart skipped a beat !

Blue is my favorite color, the darker the better.

This is a flake sawn off of a much larger stone and is a conglomerate of blue rock and quartz or something that looks like quartz. There was a heavy coating of rust on the backside and can still be seen included in the quartz on the backside.
It came from somewhere in the US.

I brought it home and lapped it with a barber hone and took a shave ready razor and did 20 laps.

The razor is as sharp or sharper than it was before !!!!

Does anyone know what sort of rock is dark blue??


shiny pics are coated in oil, I have more lapping to do yet as seen in some others

rgdomingues eat your heart out !!!!

Looks like marble to me. Put some strong acid on one of the corners and check if CO2 bubbles are formed. If so, it contains CaCO3. AFAIK marble is compressed coral/sea shells etc.

arrghhh stupid connection.....

Wow! That is flat-out gorgeous.

That really is pretty, GW - and a plus if it will hone a razor.

The only blue stone that I know of is lapis (Lapis Lazuli) and here, but I sure don't know enough about it to render an opinion (other than I wish it was mine!)

-whatever

-Lou

Originally Posted by scarface

That really is pretty, GW - and a plus if it will hone a razor.

The only blue stone that I know of is lapis (Lapis Lazuli) and here, but I sure don't know enough about it to render an opinion (other than I wish it was mine!)

-whatever

-Lou

If it has a strange odour when you grind it then it is likely to be lapis lazuli, other wise GOOD SCORE!

From Wiki "Most lapis lazuli also contains calcite (white), sodalite (blue) and pyrite (metallic yellow)."

That pretty much describes the back of the stone...

Lapis is soft, this is quite hard.

Lapis would cut with a saw and this flakes like a bit of flint.

I love lapis though and would trade this of one of equal size in a heartbeat

I found several possibilities in my wanderings today.

Does anyone think it may be Corundum?
Blue sapphires are Corundum with iron and titanium included.
It did have a lot of iron oxide on the back. I suspect this is an important clue.

I thought it might be Azurite but it remained blue when heated as hot as an electric stove burner would go. Azurite should turn black.

Is there a chance that it could be some sort of Aquamarine??
It does occur in the US.

Since it has so much quartz in it I was originally thinking of granite. There is a supposedly blue granite in Wilmington Delaware but I was unable to find a pic.

I I think I may square and bevel one side. Not only would this keep the edge from boogering up a razor but would provide me with a rubbing stone to make a slurry.

Ok, I looked up sodalite
http://en.wikipedia.org/wiki/Sodalite
maybe someone can read this crap
http://www.webmineral.com/data/Sodalite.shtml

look at the shape of the crystals
http://www.webmineral.com/crystal/Is...rahedral.shtml

looks like the garnets in coticule

sodalite is 5.5-6.5 hard and the rest is probably
quartz
http://webmineral.com/data/Quartz.shtml
or orthoclase
http://webmineral.com/data/Orthoclase.shtml


course it may just be quartz also

thoughts??

Just looking at it its impossible to say. There are so many possibilities and the lighting changes with each picture. If its from the U.S you can rule out lapis or corundum. Sodalite is a definite possibility but it could still be agate or some copper mineral like chryscolia. Do a hardness test to see how hard it is.

Wiki says corundum is found at least 3 places in North America.
http://en.wikipedia.org/wiki/Corundum

how do I do the hardness test?

UPDATE!!

I just lapped it and got my ass whooped (took 2 hours) and can ALMOST get HHT off of it.

This is significant because I cant get HHT off anything but pasted strops.

Also, now that it is lapped I can feel the blue "grabbing" at the blade which would indicate that it is much more abrasive than the quartz around it.

It was so grabby I had to put oil on it to get a smooth stroke.

No it doesn't have high spots. I lapped it with 120, 220, 400, 800, 1000, and 1500 wet dry on a piece of glass.

I decided just now to try an impromptu hardness test.
Blue hone vs Swaty
I tried to gouge the blue hone with the corner of the Swaty and the other way around as well.
The winner?? The blue hone.
I ground a little flat spot on the corner of the Swaty and hardly marred the glossy finish the blue hone has.
When the tables were turned ol blue left a plow furrow down the side of my poor Swaty !

If someone has a better test let me know.