Quince marmalade

With 1-2 quinces left over from my tart below, I chopped them to tiny pieces and cooked in enough water to barely cover, until soft. During that time I added a couple of squeezed lime wedges but then feared they would be bitter so took out the wedges after a few minutes. I added 3/4 of the measure of the quinces of sugar. I cooked 20 minutes, stirring to prevent burning. I also added some vanilla extract, since I had no vanilla bean piece to use. Due to the high pectin of the quince, this gelled slightly. This is a good toast-topper. I don't know if it would work with any other fruit, though - maybe apples? But then they'd turn all brown, and not golden-pink like the quinces.