FMF - Friends of Minerals Forum, discussion and message board

[John S. White]

Here's one for Vic to scratch his head over. This is goethite in amethystine quartz from Rio Grando do Sul, Brazil. It would appear that the goethite grew first on the surface of a larger goethite-included quartz crystal, then it became engulfed by quartz. One assumes that the growth of the two minerals was almost simultaneous.

A John Koivula photo.

[silvio steinhaus]

Amethyst with various inclusions, calcite, cristobalite, goethite, and the red stuff in the picture, I do not know what it is.
The area of the photo is 14 x 12mm piece is 160 x 175mm, with many inclusions undetermined.

[vic rzonca]

It's really amazing how, on a molecular level these, these bits find themselves and arrange themselves in such a wonderful way that makes us ponder them. Simo-nucleotidic scilicic euhedral growth over goethite. I may be wrong. Just kidding, I know nothing. I still wonder what make's an inclusion. Where are it's boundaries. I would suppose it would be totally surrounded by it's binding mineral, no penetrations. Could someone clarify.

[am mizunaka]

Quartz with fluorite inclusions.

[John S. White]

The fluorite in quartz specimen just shown by Am provides an excellent opportunity to respond to Vic's question. These Madagascar specimens are really interesting because some of the fluorites are entirely embedded or inclosed in quartz and some are partially exposed at the surface. Those that are/were partially exposed are gone! The cavities are octahedral-shaped, but empty. It is very difficult to imagine how these could have been dissolved and removed via just a tiny opening where they were not covered by quartz. The piece in Am's photos beautifully illustrates this feature.

So, Vic, in my opinion inclusions do not have to be completely enclosed in a host mineral, they often extend beyond the surface. This is particularly true for extremely elongated fibrous or needlelike minerals such as aegirine from Malawi. I doubt that there is a definition in the popular literature that would exclude crystals that extend beyond the surface from being considered inclusions.

[Antonio Alcaide]

[Jean louis lebret]

A gaz bubble in a liquid inclusion (fluorite from Naica, Mexico)

[Jordi Fabre]

[John S. White]

Here is a nice inclusion in a fluorite cleavage from Cave-in-Rock, Illinois. The cleavage is about 3 cm across. The inclusion is the tiny dot just to the right of the center of the cleavage. When magnified you can see a gas bubble in liquid and under the microscope it is possible to see that the bubble is flattened against all of the six sides of the rectangular hole in the fluorite.

The magnified photo was taken by Russell Feather, gemologist in the Mineral Sciences Dept. of the Smithsonian Institution.

[vic rzonca]

That is amazing John! Great shot!

[Elise]

[Elise]

[Duncan Miller]

[Duncan Miller]

Elise

Not only heat but also unaccustomed cold can damage some included crystals (as of course can an ultrasonic bath). A Canadian dealer reportedly once lost an entire consignment of Tsumeb cerussites that shattered in the trunk of his car parked overnight in an unheated hotel garage.

Duncan

[Maxilos]

I have been looking through my collection and found this amethist. The the location I don't know, maby somewhere from Norway (bought in Trondheim). What I do know is that it has inclusions. If I remember correctly he said: "It is amethist with rutile inclusions, nice specimen!" But correct me if I'm wrong.

And I have this apophyllite from India (mayby you remember it) with heulandite inclusions.

I have also one question since haüyne is one of my favorites: Is it possible for a mineral to have haüyne inclusions?

Mark