Post by jamesp on Apr 4, 2020 8:47:42 GMT -5
The last trip to the Rio Grande I focused on collecting big tumble agate and wood cobbles that were butt solid throughout. zero defects so to speak.
No telling how much abusive 'natural tumbling' those agates/woods experienced traveling 100's of miles to south Texas.
It is also a fact that many agate amygdule eroded out of softer lava/basalt has a roundish nodule shape.
The south Rio is a an amygdule gold mine from fine agate lava fields in central US. Amygdule s are great big tumble stock...
Rocks over 1 to 2 pounds were difficult to find without severe fractures. However the fracture-free ones were darn solid tough stone.
The Woodwards collected amygdule 's bigger than basketballs off their ranch, those are long gone. Many still embedded in the basalt fields if you like hammer and rock picks.
Many simply had a sun burn patina that was 1/8"+/- thick patina that required coarse SiC since nature already shaped the stone to a cobble if that was the shape you wanted.
Here is a classic Rio tuff ass rock, some kind of petrified local weird Texas plant form. Probably not wood. Trespass stock, don't tell.
No telling since Texas had all kinds of prehistoric plants like equisetums, cycloids, ferns, palms(over 400 fossilized palm species alone), and unknown/extinct plants.
6' diameter marijuana stumps(kidding). The horsetail equisetums fragments were from +12" diameter stalks probably 50 to 100 feet tall. Not just big lizards, plants too.
Meet UGLY.
Looks like rotten pork with ebola infection, note super thin patina(typical of the hardest local Rio rock), zero fractures, smooth wear, 1078 grams, dense X10, almost zero porosity.
There was about a 2 acre 100' high knob(other side of fence, had to go) covered with these from marble size to 10 pounds, likely petrified and native to where they sat i.e. ancient high sun powered mini-forest stand growing on rich soil covered ancient limestone bedrock from an earlier ocean. Ancient Texas plant micro habitats is my number one plant collecting turn on.
Judging from density it silicified from dissolved silica from diatomaceous limestone often making a higher Mohs material like silicified corals. Instead of basalt silicification amygdule 's.
Texas rocks form both ways, so the super hard petrified woods and plant matter. Gotta love the south Texas.
Sunny side up:
Side facing ground. May grind the divots, may not.
Might be best to have a natural side to see skin and a sawn side to see the gizzards.
That's the way, skip the grinding on this one.
On scale:
I'll start a thread on it and post weight loss/time schedule hopefully as well as Benathema has done.
I may crank up the fast tumbler and spin it at high speed say 60 to 80 rpm with big SiC and 1-2 inch hard(seemingly Mohs 7.5) pre-coarse tumbled coral smalls.
Will video speedy the rotary tumbler.
6 inch inside diameter barrel if it will fit in 4 inch opening. Tape measure says 3 3/4 inches at widest point, should fit. May grind to fit, done it before.
Low 55 to 60 percent barrel fill for max grind rate. Clay of course.
No telling how much abusive 'natural tumbling' those agates/woods experienced traveling 100's of miles to south Texas.
It is also a fact that many agate amygdule eroded out of softer lava/basalt has a roundish nodule shape.
The south Rio is a an amygdule gold mine from fine agate lava fields in central US. Amygdule s are great big tumble stock...
Rocks over 1 to 2 pounds were difficult to find without severe fractures. However the fracture-free ones were darn solid tough stone.
The Woodwards collected amygdule 's bigger than basketballs off their ranch, those are long gone. Many still embedded in the basalt fields if you like hammer and rock picks.
Many simply had a sun burn patina that was 1/8"+/- thick patina that required coarse SiC since nature already shaped the stone to a cobble if that was the shape you wanted.
Here is a classic Rio tuff ass rock, some kind of petrified local weird Texas plant form. Probably not wood. Trespass stock, don't tell.
No telling since Texas had all kinds of prehistoric plants like equisetums, cycloids, ferns, palms(over 400 fossilized palm species alone), and unknown/extinct plants.
6' diameter marijuana stumps(kidding). The horsetail equisetums fragments were from +12" diameter stalks probably 50 to 100 feet tall. Not just big lizards, plants too.
Meet UGLY.
Looks like rotten pork with ebola infection, note super thin patina(typical of the hardest local Rio rock), zero fractures, smooth wear, 1078 grams, dense X10, almost zero porosity.
There was about a 2 acre 100' high knob(other side of fence, had to go) covered with these from marble size to 10 pounds, likely petrified and native to where they sat i.e. ancient high sun powered mini-forest stand growing on rich soil covered ancient limestone bedrock from an earlier ocean. Ancient Texas plant micro habitats is my number one plant collecting turn on.
Judging from density it silicified from dissolved silica from diatomaceous limestone often making a higher Mohs material like silicified corals. Instead of basalt silicification amygdule 's.
Texas rocks form both ways, so the super hard petrified woods and plant matter. Gotta love the south Texas.
Sunny side up:
Side facing ground. May grind the divots, may not.
Might be best to have a natural side to see skin and a sawn side to see the gizzards.
That's the way, skip the grinding on this one.
On scale:
I'll start a thread on it and post weight loss/time schedule hopefully as well as Benathema has done.
I may crank up the fast tumbler and spin it at high speed say 60 to 80 rpm with big SiC and 1-2 inch hard(seemingly Mohs 7.5) pre-coarse tumbled coral smalls.
Will video speedy the rotary tumbler.
6 inch inside diameter barrel if it will fit in 4 inch opening. Tape measure says 3 3/4 inches at widest point, should fit. May grind to fit, done it before.
Low 55 to 60 percent barrel fill for max grind rate. Clay of course.