jamesp
Cave Dweller
Member since October 2012
Posts: 36,281
|
Post by jamesp on Feb 23, 2013 17:38:35 GMT -5
|
|
|
Post by orrum on Feb 23, 2013 21:34:46 GMT -5
Is that coral James?
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,281
|
Post by jamesp on Feb 24, 2013 1:47:16 GMT -5
Yep.I reduced that 5 pound coral and 5 others today that had not been assasinated.And a note to anyone reducing chunks of agate for tumbling-sit in a chair like the knappers do and put a 3/4"plywood over your lap w/sheet of about 1/8 rubber nailed to it.Strike the agate w/8 once hammer.Set the chair on a 12 x 12 tarp and chip away.The tarp catches all the pieces.A folded towel or two on your lap to reduce shock.Wear protection of course. It is a most comfortable position.It takes a long time to break stuff down for tumbling.And this position creates an accurate striking position too.This is some of the other coral i reduced.Pics before heat treatment,cooking as i type www.flickr.com/photos/67205364@N06/sets/72157632836510493/
|
|
|
Post by orrum on Feb 24, 2013 11:33:51 GMT -5
James have u thought of slabbing this stuff first to get rid of the crusty stuff n then tumbling the pure pretty coral pieces? I like the look of some pieces with the frosty white stuff but also think the pure stuff would look better to some folks.
|
|
Geoff
spending too much on rocks
![*](//storage.proboards.com/forum/images/stars/star_teal.png)
Please add 1074 to my post number.
Member since December 2012
Posts: 446
|
Post by Geoff on Feb 24, 2013 12:04:45 GMT -5
Looks like some rocks may have a date with the 45/70 when I get home from Prudhoe...
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,281
|
Post by jamesp on Feb 24, 2013 12:58:32 GMT -5
Most of the tumbled stuff is rind free center sections orrum.I am totally experimenting with a wide variety,maybe 150 spots from middle Florida to south Georgia.Yes,most of the end product is free of frosty white stuff.That stuff w/out is attracting interest from knappers cause they have never seen coral w/some of these colors. Eventually i will cook larger pieces that i can slab.Slabbing first ruins it for cooking because of absorbed oil....Cooking slabbable chunks requires much longer cook times to get heat to center of bigger pieces... Catch 22. I am an amatuer in learning stage.But i know where the crazy material is and stupid enough to do what it takes to get it:> A 45/70 sounds like a cannon Geoff.Please protect your vitals.That impact changed that rock.But not visually at all.
|
|
True Grit
noticing nice landscape pebbles
![*](//storage.proboards.com/forum/images/stars/star_orange.png)
Member since January 2013
Posts: 76
|
Post by True Grit on Feb 24, 2013 13:28:38 GMT -5
Man, who's the photographer for those pictures? they are very sharp & clear. may I ask? what camera/lens very nice. Tim
|
|
|
Post by Pat on Feb 24, 2013 14:15:48 GMT -5
You shot it with a gun? They remind me of French Fries. I like the curves. I like the other shapes, too. Good idea!
|
|
|
Post by Peruano on Feb 24, 2013 14:20:44 GMT -5
Jamesp, That stuff is strikingly close to the way Pedernal Chert (Pedernal means flint in Spanish) in Northern New Mexico weathers out with freezing and thawing. Many were so thin (and curved) that I have tumbled them more or less as they came off of the ground. Its not difficult to envision why this type of material were popular for tool making and ornaments. Let me know if you want a couple of pieces to compare. Tom
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,281
|
Post by jamesp on Feb 24, 2013 18:33:24 GMT -5
That is an old D70 Nikon body got it used.F2.8-4.0 Zoom Nikon Lense.The lense is the key.I set the parameters in manual mode.Auto focused. I shoot till i get a camel hump on the histogram graph(easier to see than the led screen).Learned when i was a kid on a twin lens reflex Rolleicord manual.Thanks Tom.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,281
|
Post by jamesp on Feb 24, 2013 19:24:45 GMT -5
I was curious what would happen Pat.If you can make chips that are wild and interesting,why not tumble and polish as they are...
|
|
|
Post by Pat on Feb 25, 2013 0:19:59 GMT -5
Agreed. As pretty as they are now, they would shine if polished.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,281
|
Post by jamesp on Feb 25, 2013 7:53:32 GMT -5
They are good candidates for the tumbler Pat.They may get a richer color after heat.I will cook a few to see how they change color and what stress effects are from the impact after heating.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Feb 25, 2013 11:28:53 GMT -5
the curves are likely from the spherical shape of the shock-wave emanating from the impact point. You should see what bullets do to flesh.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,281
|
Post by jamesp on Feb 25, 2013 12:40:11 GMT -5
You are right Scott.The impact divided the rock into 3 sections.Each of the 3 had their own 'fracture agenda'.
|
|