Fossil Or Bone?

[echinoderminator]

I have a few pieces I am curious about. Can anyone direct me to a difinitive answer?

[Pool Man]

I usually use a burn test of some sort. If there is any burnt hair smell, there is still some collegen or protein or something organic. Total mineralization will usually not smell,when burnt. I know some use a hot pin to test this way. I just hold my lighter up to it. I find lots of questionable bones here in florida creeks.

Hope it helps

Dan

[Sundancer73]

Often simply the density (weight) can give a clue.. a thump with a fingernail will reveal mineralization as well.. listen for a ringing tone rather than a thunk.. then of course the 'smoke tests'..

Don't be fooled by color.. at least here in FL, black does NOT mean old..

~Mike

[tracer]

there is no "definitive answer" in many cases. some fossils, and some bones, are completely obvious. but others are not at all, and are somewhere in the "gray area" where you'll never know. there are different "tests", but at the end of the day, i personally believe a person's experience is the key to knowing. when you've seen hundreds (or thousands) of each, you just kind of have it mostly figured out. the problem with the "burn test" is this. regular bone (not teeth, don't bother with the burn test on them) is about 70% mineral, and 30% protein (collagen). when an animal dies and the bone lies around, the collagen breaks down and is eventually gone. the rate at which it goes away is highly variable based on the environment and microbial action. once it's gone, the "burn test" won't give the smell, because only mineral is being heated, not protein. but there is no magic number to how long it takes the collagen to go away, and so therefore smell or no smell does not equal less than or greater than 10K years old, which is the "formal" definition of fossil.

for me, i don't burn-test anything. i pick it up. if it's much denser than normal bone, and much harder than normal bone, i assume it's mineralized and therefore fossil. again, that's not necessarily a great assumption, because in some environments things mineralize much faster than elsewhere. one "test" i use on bones that are broken or show any wear exposing the "spongy" internal cell structure is to push a fingernail into that structure to see if it easily crushes, like recent leached bone will, or is hard and strong, like heavily mineralized bone will be. another indicator can be (but not necessarily) the color of the bone. bone isn't white and chalky around my area unless it's recent. but that wouldn't necessarily be true west or north of me, because bones in other strata mineralize differently. the flip side of what i'm saying is i have found bones that i know for a fact are fossil that are not well mineralized. but i knew they were fossil because they're from extinct animals. to me, things from extinct animals are the least questionable, followed by bones that are shiny, very dark, and completely dense because they've completely turned into chert, and then bones that have attached hard "rock" matrix on them. much of the classic "fossil" material i find will "clink" like rock (because it is) when you tap two pieces of it together. bone makes a dull "thud" sound when struck.

the more i've seen, the more complex i consider the matter to be. i would estimate that less than 20% of the bone we see in the field is fossil. and much of the fossil bone isn't worth messing with, because it's fragmented and unidentifiable as to species.