An apparatus for estimating an ambient environment at which inorganic scale will form in a downhole fluid includes a stress chamber disposed in a borehole in a production zone at a location within a specified range of maximum pressure and configured to receive a sample of the fluid from the production zone and to apply an ambient condition to the sample that causes the formation of inorganic scale. An inorganic scale sensor is configured to sense formation of inorganic scale within the chamber and an ambient environment sensor is configured to sense an ambient environment within the chamber at which the formation of inorganic scale occurs. The apparatus further includes a processor configured to receive measurement data from the inorganic scale sensor and the ambient environment sensor and to identify the ambient environment at which the formation of inorganic scale occurs.