What are these Spherilites inside of some old obsidian shards?

[Tidbits]

I'm excited to browse through and start posting in this awesome community. I thought showing some cool 3-D Spherilites inside of some arrowhead fragments I found in Northern New Mexico would do the trick.

The property on which it was found is full of Native American pottery shards, arrowhead pieces (sometimes a couple full ones), an 18th century wagon trail, an old copper mine, banded ironstone...the list goes on! Lots of good things to be found. I have buckets of obsidian pieces that are collected when we go out walking. Recently I noticed some pieces looked like they almost were turning into sand/aggregate. (Could be pretty old maybe?) and some that has sparkles inside. Under 20X magnification I saw mossy spindles, cloudy inclusions, the usual stuff. In a handful of pieces are beautiful spherical/shellfish shaped spheres wrapped in sparkly gold 'threads'. They sparkle visibly by the naked eye.

What are these 'balls' and how come these glass pieces have rocks, debris, etc inside them? I hear that obsidian can slowly 'melt' back down into pebbles. Is that the case? Or is it just normal weird old Snowflake Obsidian?

I'm quite the rookie so bare with me!

Normal scale picture 3 is normal looking pieces found onsite for comparison, picture 4 is examples of the 'spheres' and how apparent/distintive they are compared to other spots inside the obsidian/glass.

Picture 1 A (microscope) shows there is a little blue/purple light reflected from the gold strands, picture 1 C is the clearest shot.
Picture 3 A (microscope) is the best example of how GOLD and sparkly the strands are.


Any help is appreciated!

[BabaORiley]

Hey Tidbits. It looks like you have some possible debitage that has inclusions in it from volcanic activity. Definitely eye catchers. New Mex and its geology is a long way from my realm. We have some real good rockos here. Lets see what they say...

[Lindenmeier-Man]

I’m thinking impurities ... Also obsidian artifacts ( And Shards ) contain water. Every type of obsidian has its trace origins back to a quarry . There are many strange things about the material, also it’s just beautiful.

[Lindenmeier-Man]

Oh yeah, on another note. From your area description , I’d think the material came from Toledo Cerrro quarry west of the trinity test site...JJ

[Tidbits]

Thank you so much for the quick and honest responses!

"Toledo Cerrro quarry" you say? That'll give me a good starting point in figuring out where these came from and what they are.

I was thinking of impurities/debri too. Water and other things get trapped inside while it's cooling when it first formed? Facinating!

Now here's a big question....I have so many shards and bits that I still need to go through. Is it worth setting the ones aside that have these balls inside them? Or even bother looking? I've found about a handful so far that have debri, but buckets of pieces to sift through. Lol

Do you think it's worth sending these cool little bits in to a museum, etc. for study? If not I'll see if I can donate them locally or keep them as a ? in my collection safely.

I'll get posting some Banded Iron? with blue cat's eye material inside soon. It's quite the looker too! Thanks again.

[Lindenmeier-Man]

Most people keep them. To find the absolute true quarry one would have to send to UC Berkeley . That would be expensive. They do the hydration dating there too, another expensive venture. Tom Hester sends paleo points made from obsidian there in a research project that I fear he will never live to complete. The project design is to see how far the material traveled during paleo times, and from which quarry. I’m sure someone will complete the project some day, could take hundreds of years...

[painshill]

Obsidian would be almost colourless if it weren’t for the impurities. The mineral inclusions vary from irregular fragments arising from the parent rock through to more regular crystalline or aggregated clumps of mineral inclusions – usually hematite or limonite (both are iron oxides). Less frequently, mineral inclusions such as magnetite, hornblende, pyroxene, plagioclase and biotite can be present and some of those can indeed have a sparkly golden appearance.

Freshly formed obsidian is actually rather low in water content (less than 1%), which is a characteristic of natural ‘glasses’ in general. It doesn’t “slowly 'melt' back down into pebbles”. What it does do is slowly but progressively hydrate by the absorption of water if the burial or weathering conditions are right. In doing so, it ‘devitrifies’ (becomes less glassy) and progressively turns into non-vitreous perlite, which is typically dull gray in colour. During that process, it’s common for secondary fibrous minerals to also be generated and they often form ball-like spherulites. Those secondary minerals are also what create the patterns seen in variants such as snowflake obsidian.