Below is a list of the most popular gemstones this year, in case you are planning to get a ladies diamond band ring.       Sapphire The hottest mover in 2018, sapphire comes in a variety of colors, with the more offbeat ones actually garnering more demand than the classic varieties. This year, gray, teal, lime yellow, green, and slate sapphires have seen the most takers. Malachite Malachite carries a glamorous quality that is not lost on any observer, and this has helped raise it to a level of demand heretofore unseen. Artisan Jewelers are astounded at the interest it has evoked among people looking to wear the right gem to a party, wedding, or even a meeting. Bicolor Tourmaline The American Gem Trade Association says that the demand for this stone is still on the rise, despite being already high. Bicolor tourmalines are simply irresistible and great conversation pieces. It sparks tremendous natural interest and makes people want to lean in for a look.