Question: Are there any quranic ayats about aurat?
Answer: Yes, in Al-Qur'an, 024.031 (Suuratu-n-Noor) it is stated:
"ولا يبدين زينتهن إلا ما ظهر منها"
walaa yubdeena zeenatahunna illaa maa THahara minhaa.
A more or less literal translation would be "... and to not expose their adornment, except what appears." This is for other than her mahram of course (The mahram is someone one cannot ever marry, no matter what happens).
Ibn Mas^uud explained "what appears" by commenting "her clothes." Ibn Abaas said, "her face and hands." To this Abu Hanifah and Maalik added the feet, and Abu Yusuf the forearms as well. They said these areas are excused as "what appears" in the sense that it is difficult to hide them. For example, the woman needs to show her hands when going to the market and doing work around the house. Moreover, she cannot always find a way to hide her feed when walking in the streets, especially if she is poor. She also needs to show her face when entering into contracts, being a witness, etc.
... and Allah knows best.