The rate of newly synthesized osteoid mineralization can be best estimated by -

Tetracycline labelling for osteoid mineralization Tetracycline labelling is the method of choice for estimating newly synthesized osteoid mineralization in human. Tetracycline is incorporated into new areas of osteoid that are being laid down but not yet mineralized (osteoid seams) To estimate the rate of newly synthesized osteoid mineralization tetracycline is administered to the subject at two defined time points. If the time interval between the two courses is known, both the rate and extent of mineralization can be measured. Tetracycline labelling allows a distinction to be made between defective mineralization (osteomalacia) and increased osteoid synthesis (bone remodelling states) by revealing the calcification front. Other stain used for osteoid mineralization Other stains can also be used for this purpose, but they are inferior to tetracycline:  Alizarin red Calcein Von-Kossa