New and have TONS of ???

[rocksalot]

OK so I'm very new to basically everything about rocks and fossils.  And my questions might seem ridiculous to some and I'm  sorry.   OK are all rocks that have crystal inside geodes?  I know what round cauliflower looking geodes are. But are there untraditional ones that aren't round.  And I'm find huge huge coral fossils and some other that are swirly . They all seem to have quartz inside .  I guess I'm wondering are they all crystal inside and what's the best way to see without using acid and ruining the fossil itself.  Cut them? I'll attached a few pics and more tom when i goto the creek . Some are still connected to the flat rock bottom of the creek.  

[DPS Ammonite]

Please show us the top of pictured likely coral fossil below. 
 

Do you know the locality, rock formation and age?
 

 

[jpc]

the first one looks corally, but many of the others don't.  Globs of calcite crystals.

[Ludwigia]

I would agree with calcite, although the acid test would confirm that. Drip a few drops of a strong citric acid on them. If it fizzes, it's calcite. Then rinse them afterwards in water.

[rocksalot]

I don't have any idea the age . Like I said I'm very new and don't have much knowledge . I just pick up what catches my eye. I found all these in a small creek in Indiana.  

[Ludwigia]

Technically speaking, these crystal formations are not geodes, since these have a competent lining which allows them to separate from their host rock, but rather vugs, seams or maybe in some cases nodules.

[rocksalot]

Thank you . I didn't think they were geodes but I was having a hard time finding what they were called. 

[Kane]

Topic moved to Fossil ID

[rocket]

when you scratch the crystals with a nail, what happens? If it is calcite the stone will be softer, if it is petrified coral it will be (normally) harder than iron

[FranzBernhard]

Could they have something do to with these, partially:

Keokuk Geode Collecting Information (mcrocks.com)

Franz Bernhard

[Fin Lover]

Here is a map to help you with the age of the deposits: