These are no ordinary fossils (if there is such a thing): these incredible relics are made of solid opal, sometimes with rainbows of shimmering color. Australia is the only place on Earth where opalized animal fossils are found. These fossils are of global scientific interest and are among the most beautiful and valuable in the world.
How do opalized fossils form?
Opal forms in cavities within rocks. If a cavity has formed because a bone, shell or pine cone was buried in the sand or clay that later became the rock, and conditions are right for opal formation, then the opal forms a fossil replica of the original object that was buried. We get opalized fossils of two kinds:
i. Internal details not preserved: Opal starts as a solution of silica in water. If the silica solution fills an empty space left by a shell, bone etc that has rotted away - like jelly poured into a mould - it may harden to form an opalized cast of the original object. Most opalized shell fossils are ‘jelly mould’ fossils - the outside shape is beautifully preserved, but the opal inside doesn’t record any of the creature’s internal structure.
ii. Internal details preserved: If the buried organic material hasn’t rotted away and a silica solution soaks into it, when the silica hardens it may form an opal replica of the internal structure of the object. This happens sometimes with wood or bone.
Images in this order: Opalized Dinosaur tooth, Ammonite,Shell x2, Dinosaur bone, Wood, Pineapple, Mussel shell, Belemnite. Click on each to view in more detail.
A New Perspective of the Day: This is What a Volcanic Eruption Looks Like from Space
Here’s a striking view of Sarychev Volcano in Kuril Islands of Japan going through its early stage of eruption, taken from the orbit of the International Space Station in June 2009. For more info on this picture, head over to NASA’s Earth Observatory!
Mars Rover Opportunity Finds ‘Rich’ Clay Deposits: “A new study looks at chemicals spotted by a Mars-orbiting spacecraft to conclude that Endeavour Crater, which Opportunity reached in August 2011 after a 1,000-plus day, 13-mile trek across the plains of Meridian, is flush with a variety of clays, which on Earth, form in the presence of water.”
Oh good! Just think: pottery from Mars!
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This is What Happens When Sand Gets Struck by Lightning:
Fulgurites are natural hollow glass tubes formed in quartzose sand, silica, or soil by lightning strikes (at 3,270 °F), which instantaneously melts silica on a conductive surface and fuses grains together over a period of around one second. Photographed by Ken Smith.
Stonehenge is constructed from about 20 different types of rock. The stones were brought to the site at different times, over the period of 1,000 years and many of the older ones were re-arranged in prehistoric times.
The site probably had wooden structures before the stones were erected, about 2600 BC. The first ring of stones to be placed were the so-called bluestones, which are considerably smaller than the stones of the later rings which now dominate the site. The bluestones are made of dolerite, an igneous rock. Some weigh as much as 4 tons. The nearest geologic formation of that rock is 250 km away in Wales. For much of the last century, it was believed that they were transported from there by humans. More recently, the theory that they were deposited in Wiltshire by the Irish Sea Glacier has gained acceptance.
Many of the later stones, both standing and used as lintels, are called sarsens and are made of sandstone. Some of them weigh as much as 25 tons. Such stones can be found in the region; some may have been quarried about 40 km north of Stonehenge or may have been collected from surrounding areas. Sarsens are known to be scattered on the chalk downs by glacial movement. These, being softer than the bluestones, have clearly been shaped and fitted together with joints similar to woodworking. The inward-facing sides are definitely smoother than the outward-facing sides.
Various other stones at the site are rhyolite and other volcanic materials.
Read more: http://wiki.answers.com/Q/What_type_of_rock_was_Stonehenge_made_of#ixzz1sdvFuO4f
Absolutely no food or drink don’t put your backpack on the counters goggles always on gloves must be worn if that inert chemical touches you you have to shower down because otherwise you’ll die and don’t even THINK about looking at that HCl
No, really- lick the rock.
I laughed and clapped at the same time.