Brazilium

Brazilium also known as "Brazil Sand" is found in Brazil. To reach Brazil you must buy 3 bombs located in "Not Black Market" (which can be found in Desert Island). Then place those three bombs on the ice gates, located on the three icebergs located between the Main Island and the Desert Island. Once you do that there will be a portal leading into Brazil. The Brazilium is found near the center of Brazil forming a half-circle.

If you're going to eat Brazilium, use the Sand Eater's Extraordinaire which is located in Equipment Emporium and has a whopping price of 900$. Your temperature will be dropped to -666, or -333 with HEV suit equipped.

Brazilium sells for 140 a piece, making it the 2nd best sand in the game right under Uranium.