From the description of MediCrystal amethyst Bio-Pillow it appears that this must be a cover filled with small amethyst crystals covering a foam pillow. Is this correct?

Yes, amethyst pillows consist of 2 parts, the core insert made of either special heat resistant HARD foam for FIRM cervical support or SOFT memory foam for GENTLE support, and the valuable cover with precious natural tumbled crystals of amethyst, jade, and tourmaline-infused along the whole length of the pillowcase.

The terms SOFT and HARD are used relatively, as, of course, all the pillows with stones in the upper layers feel rather hard.

These pillows are supposed to be hard; they are not built for comfort or long procedures. Of course, everybody is different, and some customers may start sleeping on them right away, but most use them occasionally for short-duration, more therapeutic sessions.

HARD MediCrystal Bio pillows may provide a better, more elevated head and neck position during FIR heat therapy sessions. These pillows are usually the preferable choice for high-heat detoxification procedures on the FIR mat.