China and India are so far into frenemy zone that they may never join forces to topple the dollar

• The BRICS group of emerging nations is exploring the idea of a common currency.
• But China and India — the two biggest economies in the bloc — often can't get along.
• The economist who coined the "BRIC" acronym said the currency idea seemed "crazy."

Whether it's the Chinese yuan or gold or even bitcoin, a discussion about alternatives to the US dollar as the world's reserve currency has been raging for over a year.