Glass material with darker areas Cycles I'm modelling a nutella pot, however I have a rendering problem.


As you can see I have a dark spot around the glass pot, my shading render is very simple though :



Also, I made the nutella model and the pot to intersect as saw in the Blender Guru donut tutorial series so there are no arctefacts. I tried to play with Light Paths values but it didn't changed a thing.
I'm clueless here.

Edit

Here is the .blend file :
https://drive.google.com/open?id=1raZvaCW-5wCaXbtoebrNK1KYopJt6opm
I've recreated your scene, and after examining the renders, it seems that the HDRI/Scene that you've created for lighting is causing the dark spots;



Try using another HDRI, or rotating the view, to see what I mean. I'm using this HDRI;



Which can be found in various resolutions here;

https://hdrihaven.com/hdri/?c=indoor&amp;h=lebombo

Edit:

I see. Forgive me, I don't eat gnutella, and so our bottles were totally different. While mine was perfectly round, yours has a very unique (and by the way nicely modeled) shape;



Your specific issue is the table (you didn't pack the images, so this is going to look a bit odd);





If I change the table to a darker color, you see that the issue with your bottle isn't dark parts, it's an especially light table, contrasting against a dark background;



I bet you could replicate these results in real life with a bottle of gnutella and a table.