This one has a small chip at the top edge, hence the mark down.
Blue Diamond Synthetic Crystal (Glass). Put these on your window sill and let the light shine through. See the rainbows on your wall.
Blue is the theme in the West sector of a Feng Shui Bagua map. This would go well there.
We have heard it said by those who know stuff, that synthetic crystals and gems often times carry a similar vibration of the real thing.