What is the ruling on the glitter found in makeup; does it constitute a barrier that prevents ablution, and is it obligatory to interrupt the prayer and repeat ablution if I notice it during prayer, having forgotten its presence?

It is not possible to definitively determine that the referred-to glisten constitutes a barrier without observing it. However, if one discovers, during or after prayer, that a small glisten on the ablutionary limbs was not reached by water, they should interrupt the prayer – if they are in it – and repeat both the ablution and the prayer. This is based on the Hadith of the Prophet, peace and blessings be upon him: "The Prophet, peace and blessings be upon him, saw a man praying, and on the top of his foot there was a glisten the size of a Dirham that water had not touched. So, the Prophet, peace and blessings be upon him, commanded him to repeat the ablution and the prayer." Some jurists, however, overlook a slight barrier.