Lithium metaphosphate, LiPO₃

Rapid dehydration of lithium dihydrogen phosphate yields the metaphosphate as a glass-like solid, readily soluble in water, and of density 2.226, this form being probably a mixture of several modifications. Slow dehydration of the dihydrogen salt, or slow cooling of the fused glass-like variety, produces a crystalline modification of slight solubility, and with the density 2.461. It melts at low redness, and on slow cooling the vitreous form is produced. The crystalline modification yields double phosphates with ammonium, potassium, and sodium.