Section 18. Classes of Real Property for Assessment Purposes. —

For purposes of assessment, real property shall be classified as residential, agricultural, commercial or industrial and also as mineral in the case of lands.

Mineral lands shall be further classified as follows:

1. Metallic mineral lands, which shall include:

   1. Patented lode mining claims, producing or non-producing;

   2. Unpatented producing lode mining claims which may be patented;

   3. Unpatented non-producing the lode mining claims which may be patented;

   4. Patented placer mining claims, producing or non-producing;

   5. Unpatented producing placer mining claims which may be patented; and

   6. Unpatented non-producing placer mining claims which may be patented.

2. Non-metallic mineral lands, which shall include:

   1. Patented, producing or non-producing;

   2. Unpatented, producing which may be patented; and

   3. Unpatented, non-producing, which may be patented.

Definition of Terms. — "Patented" mineral lands are those lands covered by a duly issued mineral patent signed by the President of the Philippines.

"Unpatented" mineral lands are those lands which were located as mining claims under the provisions of the Philippine Bill of 1902 but are not yet covered by a mineral patent.

"Producing patented mineral claims" are those claims producing minerals for commercial purposes.

"Non-producing patented mineral claims" are those claims which are only in the stage of exploration and development and has not produced minerals for commercial production.

A "lode mineral claim" is a parcel of mineral lands containing a vein, lode, ledge, lens, or mass of ore in place which has been located in accordance with law.

A "placer claim" is that which does not come under the definition of "lode mineral claim."

"Placer deposits" are in loose, fragmentary or broken rocks, boulders, floats, beds or deposits.

"Metallic" deposits are those which contain any of the metallic elements or minerals, or their combination, such as gold, silver, platinum, tin, chromium, iron, manganese, copper, nickel, lead, zinc cinnabar, tungsten and the like.

"Non-metallic" deposits are all other deposits not covered by the above "metallic deposits".

In case of conflict between the above definitions and those appearing in the Mining Act as amended, the latter shall prevail.

Special Classes of Real Property. —

All lands, buildings and other improvements thereon, actually, directly and exclusively used for educational, cultural, recreational or scientific purposes, as well as hospitals not owned and operated by the government or by any of its instrumentalities, shall be classified as special.