Read "Mirrors" at The Eldritch Dark:
This sonnet from Clark Ashton Smith (CAS) introduces an unusual rhyme scheme in the closing sestet. The opening octet uses the ABBA ABBA rhyme scheme typical of the Italian sonnet, but the sestet seems to break with tradition by following a CDE CED scheme. None of this really impacts the enjoyment of the poem, but it's an interesting technical variation on the common Italian sonnet form.
CAS makes extensive usage of internal (aka middle) rhyme throughout these lines, which lends a hypnotic effect to the reading. That technique works well with the poem's subject matter, as the reader is transported through visions of all the exotic places and events that mirrors have witnessed.