Question-Exposing crystallization?

[Jonelle 41]

*Disclaimer I am very new to this please explain things like I am 6 *

This little guy looked almost this beautiful when I found it.. I think the ants cleaned most of the limestone off.. all I did was hand polish both sides with various grit wet sandpaper, followed by a wash with dish soap and water in an ultrasonic cleaner.. the one side still has a bit of limestone which I wasn't sure if I wanted to remove or not so I polished it.. I Was wondering what the best way to expose some more of the crystals would be? I don't know what tools or anything to use and I don't want to mess it up.. should I try it on the limestone side first? Or maybe leave it? It seems pretty solid so I don't think it would be easy to mess it up too much, but I could be wrong.Thanks  also, would anyone have a guess on how old this might be? Found in Sarasota, FL.  I hope this is the right place to post questions!

[DPS Ammonite 3,383]

You can try to break or saw the fossil to expose more crystal in cross section but I would not do that. You would destroy your fossil; it is nice the way it is. Your fossil is a steinkern. Sediment or precipitated minerals were deposited inside the empty space of a coiled gastropod forming a steinkern. The original shell eroded away. Since you polished it with sandpaper, the crystals are most likely calcite. Try scratching them with a knife. If the knife scratches them, calcite is likely, if not scratched they are probably quartz. As for age, rocks in the Sarasota area vary from recent to Oligocene, 34 million years ago.

 

Cheers,

 

John

[Jonelle 41]

Thank you so much @DPS Ammonite. That was a clear explanation i can grasp! I don't think it's calcite..I'm thinking it is quartz, the sandpaper didn't do much to the fossil, just smoothed it out..especially smoothed the side with the sandstone or limestone..  I'm actually not even sure what it was. I will attach the original photo... I have a lot of these that are still inside of the stones...is it a terrible idea to put them into vinegar if they are in fact quartz? I don't have any proper tools and I would like to quickly dissolve away the matrix, I am not concerned if I ruin a few in order to test, I just wasn't sure if it would hurt them..I would take it out if it reacts like calcite... thanks  

[Ludwigia 6,973]

Don't worry about putting them into vinegar. Keep a close eye on it and if it starts to bubble, then take it out again and you know it's calcite. Nothing bad can happen in such a short time. Some mineral dealers even lay their colorful calcite blocks in muratic acid for a short time, which makes them smooth and shiny.

[Jonelle 41]

@Ludwigia I noticed that! I dropped a few unknown rocks into some acid and yanked the ones that started bubbling... the texture changed almost immediately! 

[Ludwigia 6,973]

9 minutes ago, Jonelle said:

@Ludwigia I noticed that! I dropped a few unknown rocks into some acid and yanked the ones that started bubbling... the texture changed almost immediately! 

 

You sure do learn quick! I must say, it's a pleasure having you here.

[Jonelle 41]

Thanks  @Ludwigia I have been trying to learn to identify the rocks& minerals on my own for a couple of weeks now, I got tired of posting to rock forums as they seem to think everything is quartz  scratch testing isn't always reliable on rocks, apparently- especially if I found something harder than quartz- I did buy a cheap diamond tester but I'm pretty sure it isn't reliable. .. And now that I know I have fossils too.. It is just a lot to take in.