Vug geodes or Vug quartz

[lightdragon]

ok here are several groups of geodes.

1 . thunder eggs: basically it's a volcanic projectile that has cooled fast so that it forms
solid quartz mass inside. Because of different cooling it forms a "rind"
around the quartz-agatized material.

More info see Wolfsong's post
http://mysticwicks.com/showthread.php?t=176727 not to mention he put up cool pics of them:abanana:

2. Geode: like the thunder egg it is a volcanic projectile , but has cooled more slowly than the thunder
egg and has an air pocket inside. This results is the growth of crystals inside the air pocket. The outside rind cools
quickest, then a material similar to the thunder egg is formed but the
cooling is slower to form crystals inside the air pocket.


now we get to (ta da) Vugs.

3. Vug is lava flowing form a volcano (instead of being a projectile )forms air pockets. It could be just air or water that forms the pocket. Due to
the differential cooling caused by the air pocket crystals grow from the
surrounding material and a thin rind is formed from the same material.
Usually the rind material is still super hot forming a glass material. Since
the lava is basalt the rind is a very dark glass. very similar to obsidian.

Vug Geodes or Vug quartz . this is where the cavities are called "vugs" and often are surrounded by massive quartz. When removed from the matrix , the main part can be completely swept away. The "rind" doesn't have to be thick or even exist , although usually there is a least something around the perimeter.

[Wolfsong]

here are 2 more links which previously discussed geodes... the first gives basic examples of different types and price ranges....

http://mysticwicks.com/showthread.php?t=133557&highlight=geodes


the next looks at them from the perspective of small caves and how they relate to us in that context...

http://mysticwicks.com/showthread.php?t=138013&highlight=geodes

[lightdragon]

forgot about those. thanks. But I wanted to talk more about vugs.

Well at least I didn`t forget about your post on thunder eggs. i don`t think i have ever saw such beautiful speciems

[Wolfsong]

I've always thought of vugs and geodes as the same thing even though the creation process is different.... I've always looked at pockets within rock as caves of one form or another but vugs do raise interesting questions.... I guess my concept of a vug would be a cavity in between layers of rock caused by a seismic event of some kind or even a void formed within a lode due to water percolating through rock strata..... you got me thinking ... thanks!!! :)

[DracoJesi]

ok here are several groups of geodes.

1 . thunder eggs: basically it's a volcanic projectile that has cooled fast so that it forms
solid quartz mass inside. Because of different cooling it forms a "rind"
around the quartz-agatized material.

More info see Wolfsong's post
http://mysticwicks.com/showthread.php?t=176727 not to mention he put up cool pics of them:abanana:

2. Geode: like the thunder egg it is a volcanic projectile , but has cooled more slowly than the thunder
egg and has an air pocket inside. This results is the growth of crystals inside the air pocket. The outside rind cools
quickest, then a material similar to the thunder egg is formed but the
cooling is slower to form crystals inside the air pocket.


now we get to (ta da) Vugs.

3. Vug is lava flowing form a volcano (instead of being a projectile )forms air pockets. It could be just air or water that forms the pocket. Due to
the differential cooling caused by the air pocket crystals grow from the
surrounding material and a thin rind is formed from the same material.
Usually the rind material is still super hot forming a glass material. Since
the lava is basalt the rind is a very dark glass. very similar to obsidian.

Vug Geodes or Vug quartz . this is where the cavities are called "vugs" and often are surrounded by massive quartz. When removed from the matrix , the main part can be completely swept away. The "rind" doesn't have to be thick or even exist , although usually there is a least something around the perimeter.

thanks, I get it now I think... but I don't think my rock is a vug, because I don't a visiable cavity, of course, it may not be 100% of the original stone, my aunt took pics with her cm, so I should be posting soon :)

I think I got a thunder egg two.... it's eaither a hard agate or quartz, I think the inside of this geode is agate though because it has that "outer ring" I usually see on Agates.... but it could be quartz..... it looks alot like quartz, the inner layer is huge, the "rock" is literally a samll crust and the rest is a solid crystal, I love it :)

I haven't done any hardness testing or anything, I misplaced my book, I believe quartz has a hardness of 7, like Amethyst, but I totally forget about Agate.....

I'll post that pic to.


I've always thought of vugs and geodes as the same thing even though the creation process is different.... I've always looked at pockets within rock as caves of one form or another but vugs do raise interesting questions.... I guess my concept of a vug would be a cavity in between layers of rock caused by a seismic event of some kind or even a void formed within a lode due to water percolating through rock strata..... you got me thinking ... thanks!!! :)

same here, in fact I've also called vugs and thundereggs, geodes, thinking a mineral composition and formation cause the different looks, I didn't know they had names for the different types of geodes...

[Wolfsong]

took a trip to the university today to talk to the geology prof.... seems even within their circle there are no hard defined lines seperating vugs, geodes, pockets, crevises or caves. His conclusion are all are caves which are formed differently. Geodes to him implies circular concretions (usually volcanic) with hollows lined by minerals either the same as the outer shell or by different minerals. Vugs to him implies any pocket/crevise or cavity within rock strata or created within a lode by displacing one mineral and gradually filling it with another.

[lightdragon]

thanks, I get it now I think... but I don't think my rock is a vug, because I don't a visiable cavity, of course, it may not be 100% of the original stone, my aunt took pics with her cm, so I should be posting soon :)

I'll post that pic to.



I`ll be waiting.