Solubility of gypsum powder: slightly soluble in water, soluble in acid, ammonium salt, sodium thiosulfate and glycerin

石膏粉的穩定性：加熱至150℃時失去1.5H2O而成半水物(熟石膏)，繼續加熱至163℃失去全部結晶水變成無水物

The stability of gypsum powder: when heated to 150 ℃, it will lose 1.5H2O and become hemihydrate (anhydrous gypsum). If heated to 163 ℃, it will lose all crystal water and become anhydrous

石膏粉的毒性：無毒

Toxicity of gypsum powder: non toxic

石膏粉的應用：用作密封膠的填充劑或用于配置無機膠黏劑

Application of gypsum powder: used as filling agent of sealant or preparing inorganic adhesive

加熱時存在3個排出結晶水階段：105~180℃，首先排出1個水分子，隨后立即排出半個水分子，轉變為燒石膏，也稱熟石膏或半水石膏。200~220℃，排出剩余的半個水分子，轉變為Ⅲ型硬石膏。約350℃，轉變為Ⅱ型石膏Ca[SO4]。1120℃時進一步轉變為Ⅰ型硬石膏。熔融溫度1450℃。

During heating, there are three stages of discharging crystal water: 105 ~ 180 ℃, first one water molecule is discharged, and then half water molecule is discharged immediately, and then it is transformed into calcined gypsum, also known as anhydrite or hemihydrate gypsum. At 200 ~ 220 ℃, the remaining half water molecules are discharged and transformed into type III anhydrite. At about 350 ℃, it is transformed into type II gypsum CA [SO4]. At 1120 ℃, it is further transformed into type I anhydrite. The melting temperature is 1450 ℃.

石膏及其制品的微孔結構和加熱脫水性，使之具優良的隔音、隔熱和防火性能。

The microporous structure and heating dehydration property of gypsum and its products make it have excellent sound insulation, heat insulation and fireproof performance.

凝結硬化快，凝固時體積微膨脹，這一特性使石膏制品的表面光滑、尺寸精確、形體飽滿、裝飾性好，干燥時不產生收縮裂縫，加之石膏制品潔白、細膩，特別適合制作建筑裝飾制品。孔隙率大，由于硬化體孔結構的特點，使建筑石膏制品具有表觀密度小、質輕，保溫隔熱性能好和吸聲性強等優點，還具有一定的調溫濕性 。

This characteristic makes the surface of gypsum products smooth, accurate in size, plump in shape, good in decoration, and does not produce shrinkage cracks when drying. In addition, gypsum products are white and delicate, so it is especially suitable for building decoration products. Due to the characteristics of the pore structure of hardened body, building gypsum products have the advantages of small apparent density, light weight, good heat insulation performance and sound absorption, and also have certain temperature and humidity regulation.