Alunite is an analog of Jarosite, where aluminium replaces Fe. Small deposits of alunite and jarosite were also discovered. Later weathering exposed a variety of minerals such as kaolin, alunite, and jarosite. The minerals are actinolite, montmorillonite, saponite, jarosite, halloysite, szomolnokite and magnesite. The alunite supergroup includes the alunite, jarosite, beudantite, crandallite and florencite subgroups. In 2004, "Opportunity" detected the mineral jarosite. CRISM, the spectroscope on the MRO, found hydrated sulfates, jarosite, and hematite. Associated minerals include bismutite, mica, jarosite, alunite, cerussite, atacamite, connellite. Ammonia is then added to remove potassium and iron as jarosite (KFe (OH)(SO)). Associated minerals include melanterite, epsomite, jarosite, gypsum, sulfur, pyrite, marcasite and limonite. The formula of this mineral water contains Plaster, Alunite, Jarosite, Realgar, Sulfur, and Radium. In the alunite subgroup B is Al, and in the jarosite subgroup B is Fe. In the Getang, Guizhou Province, China, occurrence it occurs with copper, sulfur and jarosite. Other minerals found on Mars were jarosite, alunite, hematite, opal, and gypsum. Hydroniumjarosite will only form from alkali-deficient solutions, as alkali-rich jarosite forms preferentially.