In the Hindu religious tradition, the tulsi, or holy basil, plant serves both as an important symbol and also as a popular medicinal remedy.
Diamond use to be the hardest known natural substance now it is the mineral lonsdaleite at 58% stronger then diamond is the first the second hardest is wurtzite boron nitridâ¦e at 18% stronger then diamonds they are both extreamly rare natural minerals sources http://www.newscientist.com/article/dn16610-diamond-no-longer-natures- ...
However, this metal is not the most expensive substance in the world. You probably knew that gold is not the most expensive stuff in the world in terms of grams. Not even platinum. Try a new look at the most expensive substances by weight. Vote the best in order to establish the winner in The Most Expensive Substances in the World.