a geochemist in the field takes a small sample of the crystals of mineral compound from a rock pool lined with more crystals of . he notes the temperature of the pool, , and caps the sample carefully. back in the lab, the geochemist dissolves the crystals in of distilled water. he then filters this solution and evaporates all the water under vacuum. crystals of are left behind. the researcher washes, dries and weighs the crystals. they weigh .