The most difficult sand riddlesGeology quiz
What is the largest sand desert in the world?
Rub' al Khali
The Rub' al Khali desert is the largest continuous sand desert in the world, encompassing most of the southern third of the Arabian Peninsula. The desert covers some 650,000 km² (250,000 sq mi) including parts of Saudi Arabia, Oman, the United Arab Emirates, and Yemen.
This photo has been taken at a seaglass beach in Hawai'i. How is the sea glass formed?
from lava droplets that fall to the sea during land volcano explosions
in deepwater volcano explosions
during lightning strikes
Sea glass beaches are created from years of dumping garbage into an area of coastline. Sea glass begins as normal shards of broken glass that are then persistently tumbled and ground until the sharp edges are rounded.
Where are such formations usually found?
in coal mines
in extinct volcanoes
Desert rose is the colloquial name given to rosette formations of crystal clusters of gypsum or baryte which contain abundant sand grains. Desert roses occur when the crystals form in arid sandy conditions, such as the evaporation of a shallow salt basin.