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Let's Rock => Prospecting => Topic started by: Michael on November 09, 2018, 03:29:32 PM

Title: Rock Breaking Chisels
Post by: Michael on November 09, 2018, 03:29:32 PM
Here in AZ I was on a field trip awhile back looking for rhyolite (green lizard).  I use mostly Eastwing hammers and a chisel, but for the life of me, that stone beat me as much as I beat it.  I never saw such a hard stone, or was it my tools?   I only have a 10" saw, so I am not looking to break up boulders, only pieces off of them.  I tried my pry bar, everything.  Got some shards when I slammed my cross peen sledge hammer / 12lbs into the stone.  Other than that it was not a productive day. Up to now, splitting agate and jasper has worked for the most part.  Onyx, calcite and other materials work well.  I know they are much softer.  Rhyolite must be 7+ on the MOHS.  I did not see any cleavage evidence on the stone as well. 

Anyone here use carbide tipped chisels when breaking off pieces?   I know they are expensive, but most effective things are more $$ than Harbor Freight stuff. ]That is, are they worth the extra $$ ?  I felt like I was in a prison chain gang along side a road, breaking stone, or trying too.  I bench press 180, but this stone just whipped me. Gotta say it was a great work out though.  Stayed very hydrated.  In AZ, dehydration is the kiss!
Title: Re: Rock Breaking Chisels
Post by: hummingbirdstones on November 09, 2018, 08:39:52 PM
Wait 'til you try to cab it!  I started cutting a piece of that once.  Worked forever on it and finally quit.  Too damn hard to even cut.  It's still on a dop semi-done from about 7 years ago.   :laughing6:
Title: Re: Rock Breaking Chisels
Post by: lithicbeads on November 09, 2018, 08:52:18 PM
I have broken plenty of jade boulders but nothing short of a 20 lb sledge works and then it can take over 400 well placed hits before a crack appears.For basalt breaking to get at pet wood we use big heavy pointed metal bars about 6 feet long , heavier the better and good leather gloves. Nasty work in any case. I once blew up a hill of agate  after it was drilled. We got 220,000 lbs after a week with a trac hoe. That is the way to go.
Title: Re: Rock Breaking Chisels
Post by: Michael on November 10, 2018, 11:26:46 AM
I knew that green lizard was hard rock, but did not know it was that hard.