Auckland Diamonds was created in 1998.
Auckland is a New Zealand city in the southern hemisphere
The hardest naturally occurring substance on Earth, besides diamonds, is aggregated diamond nanorods (ADNR), also known as hyperdiamond. This material is created under extreme pressure and temperature conditions and exhibits hardness even greater than that of natural diamonds. Other contenders for hardness include materials like boron nitride in its cubic form, which can also rival diamonds in terms of hardness.
Loose diamonds are called loose diamonds. When set as a group, the term may describe the setting more than the stones, i.e., pave, which is a 'pavement' of diamond stones. Otherwise multiple diamonds are simply called diamonds.
"Best" is a judgement, and you are the judge. The 'why' part of your question can only be answered by Mother Nature, She being the most prolific producer of excellence in the natural world. In diamond type, the most rare diamonds are of a Type II -- a and b. These diamonds are the 'purest of the pure' diamonds. Africa is not the only producer of these diamonds -- the Cullinan was found in Africa; but diamonds of this type are also found in India, i.e., the Koh-i-noor. You can read more, below.
Tornadoes are not given names as hurricanes are, but are often referred to by where they hit. So it would be called the Auckland tornado.
Auckland was created in 1350.
Auckland Pirates was created in 1982.
Auckland Airport was created in 1928.
Auckland Snipe was created in 1845.
Auckland Province was created in 1853.
Auckland Merganser was created in 1841.
Auckland Star was created in 1870.
Auckland Vulcans was created in 2008.
Auckland Lions was created in 2006.
University of Auckland was created in 1883.
Diamonds Diamonds was created in 1982.
Bishop Auckland Hospital was created in 2002.