Ad. [ɣ] became [w], [j] between [u], [i] and another vowel; [uɣV|iɣV] > [uwV|ijV]

Ad. [ɣ] became [w], [j] between [u], [i] and another vowel; [uɣV|iɣV] > [uwV|ijV]
Tolkien indicated that ✶[ɣ] become [w] when appearing between [u] and another vowel, and similarly became [j] when appearing between [i] and another vowel (SD/420). This is an exception to the rule that [ɣ] vanished initially and between vowels and therefore must have happened before this change. However, it must have happened after medial [w] and [j] vanished before [u] and [i], otherwise this change would have had no noticeable effect.

Reference ✧ SD/420

Order (00500)

After 00300 ✶Ad. medial [w] and [j] vanished before [u] and [i]
Before 00700 [ɣ] vanished initially and between vowels

Phonetic Rule Elements

[uɣV] > [uwV] ✧ SD/420 ([uɣV] > [uwV])
[iɣV] > [ijV] ✧ SD/420 ([iɣV] > [iyV])