According my 'Shorter (2 huge volumes) Oxford Dictionary', the word 'marmalade' comes from the Portuguese word 'marmelada', a preserve made from quince (marmelo).

I have had quince jelly. In English, jelly is either what Americans call 'jello' or, as in this case, it is a jam (US jelly) made with strained fruit juice, so without any peel or pulp.