FMF - Friends of Minerals Forum, discussion and message board

[Godscreation1988]

Hello fellow forum members,

My mother brought me this geode (and another) a few weeks ago from Colorado and I am writing to find out from the forum which type(s) of mineral(s) this geode is composed of.

As many of you probably saw in my first post a few weeks ago, I did not wish to do any mechanical or chemical testing of the mineral sample I posted for identification purposes but relied on you, the Internet and observation alone to arrive at a probable identification of mimetite on red scoria.

In this case, the geode in question looks like this under: camera flash in a mostly dark room, direct sunlight outside, LED flashlight in a mostly dark room and a blacklight (photos attached), respectively.

[Godscreation1988]

Photo under direct sunlight outside...

[Godscreation1988]

Photo with flashlight shown through the geode mineral in a nearly dark room...

[Godscreation1988]

Photo adjacent to a blacklight...Note, this mineral glows a light greenish hue under a blacklight.

[Godscreation1988]

One last photo displays the mineral over a blacklight to show the presence and color of the light transmitted. As with my last post, I apologize for the poor quality photos.

Thank you for taking a look!

-Michael

[Godscreation1988]

It is worth noting that the other geode I was given does not illuminate or transmit a glow adjacent to or over a blacklight. It does transmit light and illuminate like a rough quartz crystal, for example. Please see the attached photo of the other geode, which is actually nearly ovular-spheroidal.

[Godscreation1988]

Here is a photo of the other geode, positioned over the blacklight...

[Godscreation1988]

Yet another photo of the second geode, in full sunlight outside...

[Godscreation1988]

Finally, a photo of the geode that does not glow under a blacklight with an LED flashlight beam shining through it. I call it, " The Brain". Haha.

-Michael

[James Catmur]

You can add multiple photos to a single post using this method:

https://www.mineral-forum.com/message-board/viewtopic.php?p=19493#19493

It is best to place the specimen on plain white paper - that way the camera focuses on the specimen not the background

I would think this is a quartz geode in limestone and possibly from Mexico

[Godscreation1988]

Hello James and thank you for your reply. I forgot about the advice regarding the sheet of paper thank you. Do you think both are quartz geode of some kind covered with limestone?

Here is one more photo of the first geode (I took it before your reply James) for further reference purposes.

[Godscreation1988]

This one actually looks like certain images of the sun.

-Michael

[Godscreation1988]

Last photo of the geode mineral, taken this morning. What a beaut...

[James Catmur]

Possibly, quartz minerals filled a pocket in the limestone. I have quartz echinoid fossils where quartz filled the cavity left by the fossil. I have also collected amazing chert (a form of quartz) forms where it filled cavities in chalk.

[Godscreation1988]