The Sahara covers most of the northern half of the African continent along the Tropic of Cancer and makes up about 8% of Earth’s total land area. The only deserts larger than the Sahara are the Antarctic and Arctic cold deserts.

About half of the desert consists of hyperarid seas of sand, called ergs. Much of the rest consists of dry, sparse shrublands covered in a stony “desert pavement”.

Most of the desert averages less than 20 mm (0.8”) of rainfall each year; however, the region experiences long cycles of wet and dry periods thought to correspond to Earth’s axial procession. In the next 15,000 years, this cycle is expected to return the Sahara to green savanna.

An effort is currently underway to ensure environmental and food security for the region’s growing population. The Great Green Wall is a plan to plant a wall of trees along the southern edge of the Sahara by 2030.

Collecting exotic sands from around the world is a popular scientific hobby, and your collection has just begun.

Each jar contains 1 oz of Sahara sand