I would post your question on Amazon to the item page - frequently, the company who is the seller monitors Q&As and answers what they can. No way to tell solely by looking at photos IMO. Feeling with fingers can be helpful, but not foolproof either. With a vintage garment that is unlabeled, I can get additional information by doing a fiber burn test with a bit of fabric snipped from an inside seam. You probably have nowhere to snip, and a lot of these kinds of textiles are synthetic blends.