Posts tagged geology
Posts tagged geology
Uvarovite Garnets - Russia
Yes, garnets can be green. Uvarovite is a Calcium Chromium silicate with the usual garnet crystal structure. I’m still looking for some crystals large enough to add to my minerals-that-look-like-dice collection, but have yet to see any sizable specimens outside of a museum or university collection. Does anyone have any suggestions?
Pyrite Suns on Shale - Illinois
Pictures from the Mariana ArcTop: Bubbles of Molten Sulfur
Sulfur rich plumes emanate from extruded lava. In some places, the liquid sulfur is stable and forms roiling black pools on the seafloor.
Bottom: Champagne Vent (which expels liquid CO2)
Yes, liquid carbon dioxide actually bubbles into the ocean from this vent. The droplets disperse into the ocean less than 200m above the vent site. This is remarkable because the vent is at ~1,600 m depth, but liquid CO2 is lighter than water except between 3,000-3,800 m depth.
Specifically, Watermelon Tourmaline
Opalized wood. Petrified wood is basically fossilized wood that has had it’s organic matter replaced by a mineral such as agate, bit by bit, as it decomposes. The wood structure is maintained, but the wood fibers are slowly changed into stone. Sometimes a jasper, quartz, pyrite or even opal(shown above) can be found fossilized in wood.
Bay of Fundy (Canada)
The Bay of Fundy is renown for having the highest tides on the planet (16.2 meters or 53 feet). One hundred billion tonnes of sea water flows in and out of the Bay of Fundy twice daily – more water than the combined flow of all the world’s fresh water rivers. Fundy’s extreme tides create a dynamic and diverse marine ecosystem.
The Bay is renown for its coastal rock formations, extreme tidal effects (vertical, horizontal, rapids and bores) and sustainable coastal development. It is also a critical international feeding ground for migratory birds, a vibrant habitat for rare and endangered Right whales, one of the world’s most significant plant and animal fossil discovery regions.
It has been speculated that the sunstone (Old Norse: sólarsteinn; a different mineral than the gem-quality sunstone) mentioned in medieval Icelandic texts was Iceland spar and that Vikings used its light-polarizing property to tell the direction of the sun on cloudy days, for navigational purposes.
From Astronomy Picture Of The Day; May 19, 2013:
What on Earth is that? The Richat Structure in the Sahara Desert of Mauritania is easily visible from space because it is nearly 50 kilometers across. Once thought to be an impact crater, the Richat Structure’s flat middle and lack of shock-altered rock indicates otherwise. The possibility that the Richat Structure was formed by a volcanic eruption also seems improbable because of the lack of a dome of igneous or volcanic rock. Rather, the layered sedimentary rock of the Richat structure is now thought by many to have been caused by uplifted rock sculpted by erosion. The above image was captured by the ASTER instruments onboard the orbiting orbiting Terra satellite. Why the Richat Structure is nearly circular remains a mystery.