The diamond is the hardest gemstone and one of the most valued. It is said diamonds are good for coughs and mucus problems. Diamonds are the symbol of innocence and constancy. Usual for engagement ring. Diamond does supplement the energy of other gemstones. The Diamond will increase the power of the Emerald and the Amethyst to a higher level. Healers often have rings or necklaces set with Diamonds surrounding the Amethyst. Care must be used when wearing a Diamond necklace as it can block the energy flow if the wearer has negative thoughts or feelings.