The Collaborative International Dictionary of English v.0.48:

Unalloyed \Un`al*loyed"\ ([u^]n`[a^]l*loid"), a.
   Not alloyed; not reduced by foreign admixture; unmixed;
   unqualified; pure; as, unalloyed metals; unalloyed happiness.
   [1913 Webster]

         I enjoyed unalloyed satisfaction in his company.
                                                  --Mitford.
   [1913 Webster]

WordNet (r) 3.0 (2006):

unalloyed
    adj 1: free from admixture; "unalloyed metal"; "unalloyed
           pleasure"

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "unalloyed":
   absolute, bare, clarified, clear, distilled, naked, neat, perfect,
   purified, rectified, sheer, simple, straight, unadulterated,
   unblended, uncombined, uncompounded, uncorrupted, undiluted,
   unfortified, unleavened, unmingled, unmitigated, unmixed,
   unqualified, unsophisticated, untinged