GeologyRocks

I don't think that is granite, and if it is a fossil it simply can't be, because granite is an igneous rock (melted at probably 1100 deg C)

The other structure/texture is interesting.  I don't think I've seen anything quite like it before.  It could be a fossil egg - certainly looks that way. 

Come on Ben/Jon - anyone.  Any ideas?

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

More photos of the texture if that helps.

The first 8 I took outside for some better lighting.

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Then I got the rock wet

And the thing is covered in silver/gray "sparkles".

This is just a theory looking at the bottom of the rock which has the most unique texture. I look at it and think of an egg snugged up against a side of a nest. Its rounded out on the bottom and just has an organic look to it. It looks like whatever environment it was sitting on, (dirt, twigs, grass) those textures got imprinted into the bottom of it. Thats my theory if it was an "egg". lol

Scale Bar Please

The only time I've ever seen a texture like this before was in thin section and it was a quenching texture, caused when igneous rock was colled rapidly. But that was in thin section I've never seen it in a hand specimen.

Mt fisrts thought was some sort of lava bomb, but it's to corse grained for that.

It's not egg shell, fossilised egg shell has a very different texture. If you're interested I can send you some links?

From the pictures you;ve taken I'd guess at a coarse grained, crystalline rock of igneous or metamorphic origin.

I'm sure I saw something like this in Cyprus, I'm going to check through my pictures now!

Leah 

A lava bomb i assume would be solid where as this is hollow for some reason??

I looked at a bunch of egg photos and some you could see different textures and others just looked like plane lil boulders. lol but they said the shell is very thin so yea we can probably stray away from the egg idea since the sides of this rock are so thick lol

I couldn't see any quartz in it Leah.  Thats why I said I is unlikely to be granite.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

The close-ups look like gabbro to me, but how it managed to achieve an egg-shape is a puzzle;  it's either been carved or it's formed as a crust inside a vesicle (gas bubble) but I am groping around here.

Right, 

I just got my husband to have a look (he's a structural.hard rock so he's way more qualified than me) and he's suggested that the shape has come from it being in an area of incredibly high winds (take a look and the Antarctic rocks as an example, they're weathered to some very odd shapes just like that one, they've got some good examples in the Bear Grylls episode when he's in the Antarctic) Either that or it's an igneous rock injected into some kind of conglomerate, that's weathered out and been eroded fromt he inside out,the roundedness of it leaves him to believe that some kind of "water errosion" has been involved.
He's also said that it looks like the crystals are plagioclase feldspar and it's a Gabbro. 

He's going to look in work tomorrow in the Igneous textures book and see if he can narrow the texture down a bit.

 But of course he could be wrong so anyone else feel free to comment :) 

No need for him to go to work he's just remembered, it's called "graphic texture" we think,

This is an example of a Gabbro with graphic texture

http://www.eoearth.org/files/165901_166000/165917/gabbro.jpg

Anyone else care to hazzard a guess?

My goodness,

This has become fun trying to figure out what the past two specimens I have have been!

 So thank you all for the useful information!!!