First thing to notice is the use of specific crystals in a tree, as each gem tree will usually come with one type of crystals, thus defining its feng shui application. There is a wide variety of feng shui gem trees on the market, from amethyst gem trees to agate and even pearl and coral trees. For example, citrine is a stone used for wealth and abundance purposes in feng shui, so a citrine tree will be used in the Wealth area, which is the Southeast area of your Bagua. A jade gem tree can be used for health in the East. A rose quartz is obviously for heart matters, love and romance, and is good in the Southwest area of the Bagua. Sometimes you will come across a colorfully mixed gem tree, which is excellent for use in your Children and Creativity area.