The mechanism of spontaneous resolution of 1,1'-binaphthyl (1) depends on two properties of this unique, atropisomeric hydrocarbon: a moderate rotational energy barrier that separates the enantiomers and the existence of a conglomerate solid that is more stable than the racemic compound at the freezing point of the liquid (158.0 ^oC). Accordingly, fusion of the racemic liquid typically results in the optically active conglomerate (i.e. containing unequal amounts of the R and S atropisomers isomers). On the other hand, the racemic compound is the more stable crystalline form at room temperature. Thus, an inversion of the relative stabilities of the conglomerate and racemate occurs between the freezing point of the liquid and about 25 ^oC. The point at which this occurs has been estimated to be 78 ^oC. Since this stability inversion temperature (T_I) is a key component of the mechanism of the spontaneous resolution of 1, the present project was designed to establish a more precise value for it. Toward this end we have performed a series of crystallizations of 1 from DMF at temperatures that bracket the estimated T_I (i.e. 65.0 ^oC to 90.0 ^oC) and analyzed the resulting solids using polarimetry and differential scanning calorimetry.