性状  白色单斜结晶或结晶性粉末。无气味。有吸湿性。128℃失去1 1/2分子结晶水，163℃全部失水。溶于酸、硫代硫酸钠和铵盐溶液，溶于400份水，有热水中溶解较少，极慢溶于甘油，几乎不溶于醇和多数有机溶剂。有刺激性。
密度:2.32
   
质量标准   　　　Q/(HG)SJ 745-1997
项目Item                                        分析纯        化学纯
                                                 (AR)          (CP)
含量(CaSO4·2H2O)Assay,%　　　                  ≥99.0         97.0
澄清度试验Clarity                                 合格         合格
盐酸不溶物盐酸不溶物lnsoluble in dilute
hydrochloric acid,%                             ≤0.025        0.05
氯化物(Cl)Chloride,%                            ≤0.002        0.005
硝酸盐(NO3)Nitrate,%                            ≤0.002        0.005
铵盐(NH4)Ammonium,%                             ≤0.005        0.015
碳酸盐(CO3)Carbonate,%                          ≤0.05         0.1
铁(Fe)Iron,%                                    ≤0.0005       0.001
重金属(以Pb计)Heavy metals,%                    ≤0.001        0.002
碱金属及镁(MgO)Alkali metuls and                ≤0.2          0.5
magnesium,%                           

ACS级
项目名称Item                                                   ACS Grade
含量(CaSO4·2H2O)Assay                                         98.0-102.0%
稀盐酸不溶物Insoluble in dilute hydrochloric acid              ≤0.02%
氯化物(Cl)Chloride(Cl)                                         ≤0.005%
硝酸盐(NO3)Nitrate                                             Passes test
碳酸盐(以BaCO3计)Carbonate                                     Passes test
重金属(以Pb计)Heavy metals(as Pb)                              ≤0.002%
铁(Fe)Iron(Fe)                                                 ≤0.001%
镁(Mg)Magnesium(Mg)                                            ≤0.02%
钾(K)Potassium(K)                                              ≤0.005%
钠(Na)Sodium(Na)                                               ≤0.02%
锶(Sr)Strontium(Sr)                                            ≤0.05%
贮存  密封保存。
用途  氮肥生产分析微量一氧化碳和二氧化碳和二氧化碳作吸湿剂。涂料，人造象牙，油漆，造纸，染料，印花，冶金，处理水。
联合国编号  
Risk：  
Safety :  S24/25
Hazard :