Diamond Month is a term used to refer to APRIL, which is the traditional birthstone month for diamonds. The term is derived from the first letters of the names of the three gemstones associated with APRIL: diamond (D), lily (L) and emerald (E). The first two letters of the name of the third gemstone, emerald, are represented by the letters LIL, while the first four letters of the name of the fourth gemstone, Neil, are represented by the letters NEIL. Together, these three solutions form the term DIAMOND MONTH.