Eagle Rock Plume Agate

I have. Lots of different varieties. Cab #4 in this contest. forum.rocktumblinghobby.com/thread/104066 Got one vote 😂

It's really awesome.  It wasn't that yours was bad in any way, it's that #6 knocked it out of the park on the theme.  I mean, it was a freaking ornament!!!!

I was just being silly. I didn’t really have much planned for that contest, cut that cab during the month of the theme, and just decided to submit it. Didn’t have much expectations for it tbh. Mostly just to participate

The confetti plume is really beautiful!

How Do Plumes (dendrites) form?

www.chemeurope.com/en/encyclopedia/Dendrite_%28metal%29.html

Dendrites usually form in multiphase alloys. The requirement is that the molten metal is supercooled below the freezing point of the metal. At slow cooling rates, the solidification front will be planar and stable. But, at increased cooling rates, the solidification may be so rapid that the alloy concentration at the solidification front will be different from the overall concentration. The increased concentration results in an increased melting point impeding solidification near the front. Solidification also releases energy, thus impeding solidification even more. A small distance away from the solidification front, the concentration is more favorable for solidification as well as the temperature is lower. This fact increases the solidification rate at the most protruding points, thus resulting in dendrite formation. Note also that a curved interface is less energetically favorable, thus limiting the sharpness of the dendrites.

If the metal is cooled slowly, nucleation of new crystals will be less than at large undercooling. The dendritic growth will result in dendrites of a large size. Conversely, a rapid cooling cycle with a large undercooling will increase the number of nuclei and thus reduce the size of the resulting dendrites(and often lead to small grains).

Smaller dendrites generally lead to higher ductility of the product. One application where dendritic growth and resulting material properties can be seen is the process of welding. The dendrites are also common in cast products, where they may become visible by etching of a polished specimen.

Dendrites also form during the freezing of many nonmetallic substances such as ice.

Dendrites usually form under non-equilibrium conditions.

Common dendritic metal material is nickel carbonyl, where the particles have a classical "spiky" morphology.

1dave- that just blew my mind literally. All this time I thought those plumes were fossils of plants inside a solidified goo. I had no clue.

 shame...

I wondered for a long time how they came to be, had to research it. Plumes is the wrong word, they omnly want to talk about mantle plumes, finally researching dendrites got to the answers i needed.