There is an endless bounty of eye-catching gemstones throughout the world and this spectacular boulder opal is one unique beauty that looks like a shimmering crystal encased in a tree fossil. Its opalescent sheen seeps through the cracks of the seemingly wooden rings in lustrous hues of emerald green and aqua blue. Like something out of a fairy tale, the triangular piece radiates through an organic pattern mimicking the growth rings of tree.

French Levalet is back in the streets of Paris with this new piece entitled ‘Le marchand de sable’/’The Sandman’, a rather literal interpretation of the mythical character in central and northern European folklore who brings good dreams by sprinkling magical sand onto the eyes of children while they sleep at night. Funny and smart as usual.

Perched on the snout of a crocodile, this brave frog will probably never realise just how much of a lucky escape it's had. For there's one reason the reptile's beady eye is fixed greedily on its visitor with jaws gaping wide in anticipation - it's feeding time. The crocodile had just devoured the first frog in his enclosure, but appeared unable to capture the second.

Artist Elizabeth Thompson poses next to her Blu-tack Spider sculpture at London Zoo on October 25, 2007 in London, England. The sculpture, known as “Blu-ey”, is a model of a common house spider and is completely made out of blu-tack. It is on show at BUGS! at ZSL London Zoo. The sculpture is made from around four thousand packets of Blu-tack and weighs over 200kg. (Photo by Chris Jackson/Getty Images)

“Lofoten Glow”. I was desperately searching a good sunrise spot this particular morning. Normally Storvatnet Lake is completely covered in snow, so you can only imagine my surprise when I saw these crazy ice formations almost being shot out of the frozen lake. I put my crampons on and took a big risk walking out. I could hear the ice cracking underneath my feet, and when you’re all alone in a fjord/canyon like this – the cracks are echoed and sound really frightening. Was it worth it? I sure think so! Photo location: Storvatnet, Lofoten Islands in Northern Norway. (Photo and caption by Stian Klo/National Geographic Photo Contest)

Is it a leaf? Is it tree bark? No, it’s the Satanic leaf-tailed gecko. Cleverly disguised as a rotting leaf, Madagascar’s camouflage king has red eyes, pointy horns and a taste for night hunting: it’s nature’s most devilish deceiver. The twisted body and veiny skin echo the detail of a dry leaf, which ensures the gecko blends in with its forest home. The mottled tail appears to have sections missing, as though it has withered over time. This mini-monster epitomises survival of the fittest, having adapted gradually to become today’s extraordinary leaf impersonator. (Photo by Thomas Marent/ARDEA)

Dont get catty. These roar-some images show the moment two female tigers came to blows in a bitter dispute over territory. Rarely ever seen in the wild let alone on camera, the dramatic images show a white Siberian tiger and orange-coloured tiger slashing ferociously at each others face and eyes. The intense altercation erupted into violence when the smallest of the pair, the orange striped tiger known as Shadow, attempted to expand its hunting ground. But white tiger, TiBo, wasnt willing to give up the ground without a fight and was forced to use its size and weight to put Shadow firmly back in her place. (Photo by Alex Kirichko/Caters News/SIPA Press)

This image is NGC 6543 known as the Cat's Eye Nebula as it appears to the Chandra X-Ray Observatory and Hubble Telescope. A planetary nebula is a phase of stellar evolution that the sun should experience several billion years from now, when it expands to become a red giant and then sheds most of its outer layers, leaving behind a hot core that contracts to form a dense white dwarf star. This image was released October 10, 2012. (Photo by J. Kastner/NASA/CXC/RIT)