Description
Gypsum is a relatively soft common mineral that is usually white in appearance. It may also appear yellow, brown or green tinted if impurities are present.  Where the mineral has a good crystalline structure and appears transparent it is referred to as "selenite". If it appears as fine milky blocks then it is referred to as "alabaster". Those with a parallel fibrous structure are called "satin spar". If it looks like loose soil then it is called "gypsite". Gypsum is an excellent heat insulator, fire resistant and congeals so it can be used in fire-resistant building materials or for making models. It has many applications and was traditionally used in making tofu.

Mineral Formation
(1) Formed through crystallization of hot solutions in Andesite.
(2) Forms near sulfide vents in volcanic regions.
(3) Formed by the settling of calcium sulfate solutions in sedimentary rocks.
(4) Formed through combining with man-made sulfide emissions in mud rock with higher calcium content (e.g. fossils rich in calcium carbonate).

Geographic Distribution
(1) Found in hot springs and hot liquid sediments at Beitou, Jinguashih and the Coastal Range.
(2) Found in gaps within the basalt at Penghu.
(3) Found near the sulfur gas vents of the Datun Volcano range and Gueishan Island.
(4) Found in the mud rock around Kaohsiung and Pingtung.
(5) Found in the sandstone fissures of Sanyi in Miaoli.

Mining History
Most Gypsum deposits in Taiwan are located in the east. Deposits were found in the early years by Japanese surveyors and small-scale gypsum mining was carried out near the mouth of the Siouguluan River at Jingpu in Hualien County though this has now been abandoned. Gypsum can also be produced by the evaporation of seawater so small quantities were produced as a byproduct of the salt fields. With the abandoning of salt fields gypsum production from this source has stopped. Taiwan has no natural sources of gypsum and meets all of its needs from imports.

Production
In 1959 gypsum production totaled 331 tonnes for the year, with 156 tonnes in 1960 and 194 tonnes in 1961. No gypsum mining is currently carried out in Taiwan.

Applications
(1) Plaster casts - building, medical and modeling applications.
(2) Paint and cement.
(3) Sculpting.
(4) A basic ingredient in fillers, dyes, papermaking, pesticides and tofu.

National Museum of Natural Science