Sapphire is a stone unto itself.
Its brilliance ranks it as one of the four precious stones. By national and international standard, the precious stones are as follows: Ruby, Diamond, Emerald and sapphire. All other gemstones are considered semi-precious. The rating system is based on rarity and demand.
Not are these rare precious stones of high demand and low supply, but they are also excellent to admire in your display case. They are great conversation pieces to have in your collection as you show them off to friends and family, or proudly display them in your home.
Beyond all of that, they are a great investment. They are not making any more of them, and the cost only goes up. As the mines thin and the non-replaceable supply shrinks, their value shoots up. Combine that with the fact that modern machinery and technology are depleting the supply way faster than the days of prospectors with a pick and shovel. A few sapphires, rubies, and emeralds here and there as you have a few spare dollars to invest, and you could be sitting on a very nice return on investment one day. A company may go go bankrupt anytime and wipe out the value of their stocks... but precious stones remain precious!