【Mix】 , 【mingle】 ,  【commingle】 ,  【blend】 ,  【merge】 ,  【coalesce】 ,  【amalgamate】 ,  【fuse】 denote to combine or become combined with resulting diffusion or interpenetration of particles, parts, or elements.

【Mix】 , the most comprehensive of these terms, need not imply loss of identities, but even when the elements are distinguishable it suggests a homogeneous character in the product.

So far as they differ,  【mingle】 , rather than  【mix】 , implies that the constituent elements are distinguished in the product.

【Commingle】 may suggest a more intimate and often a harmonious union.

【Blend】  may be the equivalent of  【mix】  or  【mingle】 , but usually it implies a mixing of harmonious or compatible things, a union so intimate as to obscure the individuality of the component parts and a sharing of their qualities by the resultant product.

【Merge】 still more distinctly implies the loss in the whole of the constituent elements or the complete absorption of one element in another.

【Coalesce】 suggests a natural affinity for each other in the things merging and a resulting organic unity.

【Amalgamate】 implies a tendency to 【merge】 or draw together largely as a result of contact or association and sometimes suggests effective or harmonious union more than loss of identity.

【Fuse】  stresses even more than  【blend】  and  【merge】  the loss of identity of each of the component elements, and, more than  【coalesce】 , the indissolubility of their union. It often implies a powerful cause which operates like heat melting and bringing into one mass disparate substances.