Rare Large Jasper Nodule from the Carver Agate Field

Rare Large Jasper Nodule from the Carver Agate Field

This posting is more about geology than a pretty specimen.

Bear with me as I ‘get into the weeds’ to explain why this is rare and is the subject of this posting.

How nodules form

Gas bubbles in molten lava sometimes, after hardening, leave a bubble or void in the hardened lava which may fill with a silica solution.

The silica often creates banded agates or crystal lined voids in the center of the nodule which are called geodes.

What is rare and unusual in this large specimen, is that the nodule formed in the gas bubble is essentially jasper, not agate, quartz, or other crystals.  While The Carver agate field has lots of jaspers, they are almost always formed separate from, and outside of, gas bubbles that have formed in the lava.

The process by which jasper would completely fill a large gas bubble is apparently uncommon. I have only found two large jasper-filled nodules in the last 10 years of exploration on The Carver Agate Field.

To illustrate this point, I would suggest that you look through the extensive photo galleries on the website which demonstrate it’s rarity in this agate field.

 

One Comment

  1. I have found material like that on the old Woodward Ranch back in the 60’s and also some on Lajitas Mesa.

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