The Davao and Leyte magneslte deposits are associated with serpentinized peridotites. Folded structures are common In the Davao magnesite and they form boxwork structure of veins. Some portions are replaced by opallne silica. Magneslte with associated dolomite in the Leyte deposits occur mainly as tabular bodies along open spaces with both brecciated and replacement features. The proposed modes of formation of the Davao deposits are both supergene and hypogene hydrothermal processes while the formation of the Leyte deposit is purely supergene. The Davao deposit has an estimated 741,562 MT positive reserve and 5.9 million MT probable reserve. The Leyte deposit has an estimated 457,041 MT positive reserve.

Visual upgrading of the Davao magneslte did not improve the quality because of the associated silica and the same with the Leyte magneslte because of the associated dolomite. Upgrading using the dead burned products is possible.

Calcination and trial utilization experiments were performed to test the usability of the magnesite for the refractories. The Leyte magnesite readily forms dead burned magneslte at 1740°C. Associated dolomite, however; raised the CaO contents of' the product rendering the material unsuitable for refractories. The Davao magneslte require higher burning temperature (>l740°C) to produce a DBM. Trial utilization test on this material gave good results.