Not every gemstone, you can sell at a big lump sum amount. There are some gemstones that to make big money, you must sell many kg even tons. When I say lump sum, I mean US$ 100,000 and above per piece of the gemstone. You can’t sell gems such as citrine, red garnet weighing 1 - 10 grams for US$1,000 to US$100,000 per piece.
Below are some of the gemstones that can command big prices;
From the above mentioned gemstones, if you can manage to get piece weighing between 5-10 grams per piece. You are very much assured to make big sales of between US$ 1,000 to US$ 1,000,000. But sometimes it may depend on the color.
If you may observe in auctions such as Christie's Auctions, you will discover that it is the same gemstones that I mentioned above that command big prices.
Ruby Ring 8.26ct Cushion shaped Sold at Sotheby for US$ 8.6 million
Sapphire Ring 27.54ct Step cut Sold at Sotheby for US$ 5.9 million
Burmese Ruby 29.62ct Oval cut Sold at Sotheby for US$7,338,462.HongKong April 2014
Burmese Ruby 6.04ct Sold at Christie HongKong for US$3,331,380 May 2012
Kashmir Sapphire 27.54ct Step cut Sold for US$ 5,984,474