Jump to content
Nugget Shooter Forums

Recommended Posts

Here is a little stone that has always been a mystery.

Non magnetic, very hard (8.5-9 by estimate). I polished a corner into a little window and it was nearly impossible to cut it with silicon carbide paper. Streak was white or clear. Maybe a little metallic but it was difficult to remove any material. The window was just smooth, black, almost sub metallic and glassy. Like a cross between iron and obsidian.

Found as nodules in a volcanic field in southern New Mexico. There is a white ash/mud sill under a volcanic extrusive flow that has these little strange shaped nodules eroding out of it.  Some are as big as your head down to about the size of the end of your thumb. All of them peaked, sectioned and often dotted in the center of the sections with little imperfections.

I am guessing it is an iron/silica combination of some sort. Maybe alloyed with something. The peaks and lines and dots are awesome. I can't say I have ever seen stones like it. There are lots of shapes of iron nodules in these parts but nothing quite as odd as these. I am thinking they are special in some way.

I found these rocks several years ago and have attempted to re-locate them on three occasions. So far no luck. I am headed out again in a day or two and see if I can find that spot again. 

What the heck do you think they are?

a7.jpg

 

 

  • Like 2
Link to post
Share on other sites
20 minutes ago, d_day said:

Looks like basanite, but the hardness of that stuff is only 7.

It could be. It is as hard as heck but my hardness estimate is just a wild guess. It took forever to grind a very small window about the size of a pinhead on one of those small protrusions. I might be overestimating the hardness. Let's just say it is mighty durable stuff. When I realized how hard it was I hit it with a ball peen hammer and the hammer just bounced. It did not even phase the little nodule at all even though it sat on points on the anvil.  So it is really tough.

Hopefully I will find the spot and have a bunch more nodules to play with soon. The bizarre shapes and lines are what has me riveted. I have some diamond carvers for the flex shaft tool and I will be able to whittle more away and experiment more.

Thanks for the input. You might be right. I have seen tough basanite rinds on some stones as well as basanite that was porous like scoria. I suppose it makes sense that it would form hard, wild shaped nodules too.

 

Link to post
Share on other sites

Years ago I was whacking a piece of jade with a hammer but finally gave up. Jade is tough to crack but only has a hardness of 6-7. Hardness and whackability are two different things.

 

  • Like 1
  • Haha 1
Link to post
Share on other sites
2 hours ago, Morlock said:

Years ago I was whacking a piece of jade with a hammer but finally gave up. Jade is tough to crack but only has a hardness of 6-7. Hardness and whackability are two different things.

 

Yes I agree. Sometimes hard things are brittle and sometimes softer things are more durable. I suppose what I was trying to say is it is both tough and hard. It is very hard because it resists abrasion with good quality silicon carbide paper. It is very tough because you can set it on an anvil and whack it pretty good and it will just reject the hammer blow. So it is high on the whackability scale too. I would say about a 734 or 735. It is a whackabilly for sure.

It was very difficult to get a window big enough to see the inside so I was trying to knock one of those horns off with a hammer. I wasn't hitting it to see how hard it was I was hitting it to get a look at a broken face. In doing that I realized it was extremely durable as well. 

1 hour ago, wet/dry washer said:

specific gravity?

Me am not going to do a specific gravity test on it. It is not exceptionally heavy for its size and color. In the hand it feels about right for a piece of iron rich rock. Me would estimate the SG to be about 4.5-5 but that is a wild azz guess just like the hardness estimate and the whackability scale.

It is hard. It is durable. It is aphanitic or cryptocrystalline. It is not particularly heavy for an iron rich volcanic but heavier than quartz. From the little me was able to grind off of it, it has a light streak. It is of extrusive or very low pressure volcanic origins. It is only very slightly attracted to a neo magnet. It is found as nodules scattered within a white, chalky horizon below a flow of high silica vesicular basalt several feet thick.  

Me have been back to that spot repeatedly over the last ten years and me just can't find the ledge that these things are rolling out of. Most natives would have given up. But me is headed back out to get another bite of that big volcanic trap and see if me can locate that spot and collect a few more. Me am not going to give up until me finds them again.

Me is very curious. 

  • Like 2
Link to post
Share on other sites
5 minutes ago, Greg L said:

Me interested in what you might think they are or could be

Me don't know. Me am interested in finding out. Me have no particular thoughts about what they might be and that is why me is soliciting opinions.

Me think they are crazy shaped little iron nodules of some sort. At last that is what me am going to call them until me finds out otherwise.

Me don't think they are meteorites, gold, diamonds, tektites, moldavites, alien poo or sacred seer stones. Me just like learning about things me don't know yet.

Link to post
Share on other sites

Though the shape and hardness is different along with the exterior lines...the rind almost reminds me of a weathered apache tear. Once in Arizona I located the host rock some apache tears were eroding from and it was a very porous, crumbly white stone found in the vicinity of known past volcanic zones. Maybe you could have found some type of geological hybrid specimen? Ha! Interesting shape! 

Link to post
Share on other sites
5 minutes ago, Randall said:

Though the shape and hardness is different along with the exterior lines...the rind almost reminds me of a weathered apache tear. Once in Arizona I located the host rock some apache tears were eroding from and it was a very porous, crumbly white stone found in the vicinity of known past volcanic zones. Maybe you could have found some type of geological hybrid specimen? Ha! Interesting shape! 

An "apache tear" (merkanite) is obsidian and it weathers to perlite causing the surface texture. It is found in a volcanic matrix a lot like these. And yeah, the "matte" surface and finish does resemble a merkanite. But obsidian is soft and very brittle and easy to break. They generally have a convex shape. These pieces are almost entirely concave.

I think it was formed in a similar way with different materials. Thus the similarity in appearance.

The pattern and shape is what has me going.  I want to get a few handfuls of them to tumble. 

I think basanite is probably a good guess. I am satisfied with calling it that. 

:)

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...