What is This?

[Golden Tiger]

About a month ago the family and I went to Phillip Island, and one of my son's picked this up at the beach and was using it to draw on the concrete at home. When one of his brothers came along and broke it (as brothers do). To much of my surprise it is very hard inside like a rock. It has a small cavity which you can just see in the photo which has a small crystal lining. Any idea what it might be? My first thought was coral, What do you think?

 

[Nugget]

My non-expert opinion is a bone of some sort. Could you post another picture with the two pieces put together as one?

 

[richo966]

whale bone maybe

 

[casper]

You get the same sort of stuff falling out of eroding dunes on the Mornington Peninsula ocean beaches - all weird and crooked shapes. Petrified wood is also found on a beach down near Cape Schank and the core of those specimens is identical to yours however without the limestone crust.

casper

 

[Golden Tiger]

I'll post a picture of them together when I finish work. Don't finish until 1:30am so it will be up tomorrow.

I had never thought of bone. Maybe it is.

Casper, do they have any crust at all ?

 

[The Green Wanderer]

Kinda looks like pipe clay thats been fossilised.
I find the odd rock up here like that, not usually with a crystalline centre. Mostly their red clay coloured sometimes yellowish brown or cream with centres of black stone or smaller basalt pebbles inside. Usually they look like water worn sandstone in the river until you hit them with a shovel.
Wish I had a photo of one to compare it to yours but looks similar.

 

[Golden Tiger]

Ok, so here are a few more pics.

Does anyone have any idea who i can take this to, to get a positive identification?

 

[headbut]

The shape does look like coral. Too oddly shaped to be bone

 

[G0lddigg@]

looks like petrified coral

 

[gtol29]

Ok, so here are a few more pics.

Does anyone have any idea who i can take this to, to get a positive identification?

https://www.prospectingaustralia.com/forum/img/member-images/1104/1391410931_1..jpg

https://www.prospectingaustralia.com/forum/img/member-images/1104/1391410958_2..jpg

https://www.prospectingaustralia.com/forum/img/member-images/1104/1391410997_3..jpg

https://www.prospectingaustralia.com/forum/img/member-images/1104/1391411022_4..jpg

https://www.prospectingaustralia.com/forum/img/member-images/1104/1391411047_5..jpg

https://www.prospectingaustralia.com/forum/img/member-images/1104/1391411069_6..jpg

You could try the museum they might have some info on what it could be??

 

[G0lddigg@]

actually cpuld be a whale jaw bone

 

[Dughug]

Looks a lot like flint with a calcification/limestone build up on the outside. This type of material is very prolific along the coast at Port MacDonald SA - just down the road from Mount Gambier.

 

[Golden Tiger]

Thanks guy's for all your answers but I think Dughug has hit it on the head.

After doing some research on flint and cross referenceing it with minerals found in the location I'm 95% sure it's flint.

Ahhh what a relief.

 

[heathcote]

I don't think flint would be hollow like that it is more like fossilised coral. The place to have it checked is the geology department of your nearest university or perhaps a geologist in the state government.

Thanks guy's for all your answers but I think Dughug has hit it on the head.

After doing some research on flint and cross referenceing it with minerals found in the location I'm 95% sure it's flint.

Ahhh what a relief.

 

[petesabout]

I reckon it could be Fulgerite that's had a spell in the waves. Not too sure how durable they are when meeting the surf, i've allways had the belief that they're quite fragile but you never know.
In case you're not in the know of Fulgerite, think Lightning bolt hitting the beach and turning the sand into half baked crystaline glass.

 

[Paydirt]

Hit it with abit of vinegar, if its a fulgerite it wont fizz (fused SiO2) if its carbonate based it will

 

[Matt80]

I was thinking lightning strike on first glance as well, but then wasn't sure if it should have more branching and if it would have time to form the crystals, but after looking up pics of fulgerite it looks very much like it. So +1 for fulgerite.