Predictions of lead arsenate solubility and thermodynamic stability have been based on the value of the solubility constant for a precipitate with the general composition Pb₃(AsO₄)₂. The solubility of this precipitate is high and lead arsenate is considered to be unsuitable for lead and arsenic control in the environment. Standard Gibbs energy of formation for bayldonite, duftite, mimetite, philipsbornite, and schultenite can be found in the literature from solubility studies. From these data, stability diagrams were established for the environmentally relevant lead containing solid phases – anglesite, cerussite, schultenite, and mimetite. The diagrams lead to the conclusion that mimetite is a lead arsenate that can be used for remediation techniques.