Lapidaryforum.net

Please login or register.

Login with username, password and session length
Advanced search  

News:

Welcome new members & old from the Lapidary/Gemstone Community Forum. Please join up. You will be approved after spam check & you must manually activate your acct with the link in your email

Congratulations to Sandsave and his Crinoid Cab!

 www.lapidaryforum.net

Another cabochon contest coming soon!

Pages: [1]   Go Down

Author Topic: Speaking of Patinas  (Read 2788 times)

0 Members and 1 Guest are viewing this topic.

Kaljaia

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 645
Speaking of Patinas
« on: May 09, 2016, 12:05:47 PM »

A broken stone found in a ditch beside a road.





Very distinct difference in patina between sides. Flat grinder, I think? It was in a pretty clearly disturbed area and looked like it had been driven over, so not of historical value- well displaced from whatever location and strata it would have come from.
As to the patina, I am curious to know how many strokes it would take to polish and shine a stone that much. Would a good grinding stone be carried from camp to camp? Passed down from one generation to the next? Were they 'seasoned' by use and considered more valuable the smoother they got, or less effective as the rough surface wore off?

Or is it just the result of natural weathering?
Logged


- Erika

I rock hunt in the Antelope/Ashwood area of the John Day river basin in Oregon. 90% of what I post is from this area, from private property where I have permission to hike and collect. The material I find is for personal use only, I do not have landowner permission to sell. Thanks for understanding!

Enchantra

  • Head Bead Nut
  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2651
  • Insane Bead Woman
    • Enchanted Regalia
Re: Speaking of Patinas
« Reply #1 on: May 09, 2016, 12:16:25 PM »

I am going to say this is a product of weathering.  One side more exposed than the other.
My archaeological knowledge from studying Native artifacts in college and grad school tells me this is not man made.
Logged
-Amanda
http://www.pinterest.com/amandabielski/
https://www.facebook.com/enchantedregalia/

Coincidence is G-d's way of staying anonymous.  -Rabbi David Abrahams

Sometimes when we are generous in small, barely detectable ways, it can change someone else's life forever. - Comedian Margaret Cho.

A man wearing a helmet defending his country should make more money than a man with a helmet defending a football!!!  (From an email message I received - so true!)

Kaljaia

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 645
Re: Speaking of Patinas
« Reply #2 on: May 09, 2016, 12:35:13 PM »

I am going to say this is a product of weathering.  One side more exposed than the other.
My archaeological knowledge from studying Native artifacts in college and grad school tells me this is not man made.

Thanks for the response! I'll compare it to other local rock and see if the patina is replicated, maybe from a local wildfire. The road is not traveled enough for it to be 'cobblestone' wear. Would water produce such an uneven effect? 
Logged
- Erika

I rock hunt in the Antelope/Ashwood area of the John Day river basin in Oregon. 90% of what I post is from this area, from private property where I have permission to hike and collect. The material I find is for personal use only, I do not have landowner permission to sell. Thanks for understanding!

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2610
Re: Speaking of Patinas
« Reply #3 on: May 09, 2016, 01:10:01 PM »

I assume there was a photo with this post but it is not showing for me.
Logged

Kaljaia

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 645
Re: Speaking of Patinas
« Reply #4 on: May 09, 2016, 01:48:19 PM »

I assume there was a photo with this post but it is not showing for me.

Thanks for letting me know! I swapped image hosting. Do they show up now?
Logged
- Erika

I rock hunt in the Antelope/Ashwood area of the John Day river basin in Oregon. 90% of what I post is from this area, from private property where I have permission to hike and collect. The material I find is for personal use only, I do not have landowner permission to sell. Thanks for understanding!

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2610
Re: Speaking of Patinas
« Reply #5 on: May 09, 2016, 05:48:11 PM »

Yes and the stone looks extremely well worn. I suspect just a few years could do that because the stone they ground on became worn as well. All the grit was not good for the teeth at all.
Logged

brentnewton

  • Guest
Re: Speaking of Patinas
« Reply #6 on: February 21, 2019, 03:35:21 PM »

Geological time is vast :) It strains the mind to understand.  Its not a man-made artifact .. its an artifact of time.  Vast time ... deep time. Most cobbles .. have been worked a lot of times. Over and over. And .. over.  I am in KY and have a ... serious interest in Pennsylvanian fluvial conglomerates .... lol.  Um ... think about 300 million year ago. I look at a cobbles and wonder where the hell in half a freaking continent it came from - if the continents were anywhere near where the a now (not) ... its a bit of a puzzle .. ok .. more than a bit of a puzzle.  Sure as heck ... ain't man made ya know .... just my thing ya know.  The continents were no where close to where they were ... mountains were .. nothing like are now .. deep time ... and we didn't talk about environments or atmosphere yea now.  Climate change meh ....
Logged

GoodEarth

  • Global Moderator
  • Full Member
  • *****
  • Offline Offline
  • Posts: 232
Re: Speaking of Patinas
« Reply #7 on: February 25, 2019, 10:26:28 AM »

Desert Varnish accounts for the patina.
Logged
PNW Rough Rock including
Olympic Poppy Jasper

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2610
Re: Speaking of Patinas
« Reply #8 on: February 25, 2019, 07:06:43 PM »

A forensic geologist gave me a good lesson once. I took him to a remote canyon to see an unbelievable boulder the size of a cabin. After he looked at it for a while I asked him where he thought it came from hoping to find the in situ source. He looked at me and pointed straight up and said , " About 3,000 feet that way". The rock was so dense that any stream ever in that drainage would not have been strong enough to move it but as the stream eroded it's surroundings it move toward the center of the earth. It is easy to forget about the now largely absent third dimension of our geological trips. In Washington very old large streams are often responsible for water worn stones and even fairly large sections of old river beds perched on canyon walls. New streams cut the old river beds . In Washington and Idaho these ancient stream beds can be  a wonderful source of ancient alluvial gold as often false bedrock is easily seen in the eroded stream profiles. Let your imagination go out there.
Logged
Pages: [1]   Go Up
 

Page created in 0.069 seconds with 43 queries.