This paper will discuss several aspects of how formation mineralogy can affect treatment designs. The paper will show how the mineralogy can be used to create a first good estimate of the adsorption isotherm, which is normally the primary controlling mathematical function that describes how the scale inhibitor will return from the formation. This was accomplished by first determining the true equilibrium adsorption isotherms of an example scale inhibitor on various single minerals. Short-core tests are often used to determine whether issues of formation damage might be relevant. However, this paper will show that scale inhibitors, particularly at pH less than 5, are reactive with formation mineralogy and can lead to fluid conditions not achievable in short-core testing, and therefore not generally anticipated during the squeeze treatment. Consequently, short-core tests may not always be a reliable indication of damage potential. This paper will discuss how an evaluation of the formation mineralogy can lead to insight into ways to avoid many damage mechanisms unobservable in short-core testing.