These are sweet clear crystals called Apophyllite Clusters or with fluorite which seems to create square crystals without pyramid tops. Dimensions are for the right one which also has larger crystals.
The crystals facilitate taking you into a deeper state of relaxation and receptiveness. Said to have in the treatment of asthma and any health conditions involving the lungs so can help relieve symptoms of allergies. Read more about the shape.
Do any of these prehnite clusters call to you?