Seer Stones are generally Quartz that have been naturally tumbled in rivers. This will give them a frosted look on the outside that is hard to see for the untrained eye.  Depending on the location that are found in, they can be in forms of Quartz like the Amethyst, Clear, Rose or Smokey varieties.
When these frosted stones are cut and polished on one end, these faces or “windows” show their clear inside. .
Seer stones aka Ema eggs have been used as an aid to scrying for a long time as it can show you the past, future and present by taking you deep within your inner self.  it is also believed that you can program a seer stone in order to go to a specific time so that you can access the knowledge you need from that time.  Seer stones will come to a person when they are ready and willing to take an honest look within and ready to accept the truth.