Try to make a simple stone by color test.
Collect some subjects in these colors: red, pink, brown, orange, yellow, green, blue, purple, white, black, gray.
Then put them in front of you, close your eyes and take a deep breath a few times. When you feel you’re ready, open your eyes and try to notice which color instinctively appeals to you the most.
Finally, choose a precious stone in this color. With that, the filter in the right sidebar which you find in Magic stones category will help you.