I sell crystals and minerals that can vary in shape and size but many of them are made of the same type of stone. I've seen some stores use the same description on crystals that have the same properties, it's almost like an collapsible text box, I wonder if that's done through coding. Solving this issue would help a lot since I have more than 300 different items to list and that would reduce significantly my work, as long as it doesn't affect SEO.
It depends, if you have the same product description for 2 or 3 product pages - then it's okay. However, if you have the same product description for over 10 product pages, then Google can count it as duplicate content and you can get a penalty for that. Google explicitly said that they prefer pages with distinguishable information:
Check out the detail guideline HERE
Hey, @ beatrizb, I request you to make description unique for each one if possible because going with the same description for multiple pages won't help you to get a proper ranking and traffic from google!!!