Crystal Scrying Glass

Scrying mirrors made from this type of glass are the most accurate way to discern the future events. Unfortunately, manufacturing process of glass this type was lost some 500 years ago during the crusades. Due to this fact, large scrying mirrors of this kind are extremely rare. They are either in possession of the Chroma Magical College, in private collections of wealthy people or were broken down into smaller pieces so they could be sold to as many people as possible. Chroma magicians usually start out their clairvoyance career with a palm sized shard, if they are lucky.
Glassmaking has long and rich history in Bohemia and is one of the staples of their export. It also has a big cultural significance to many regions spread thorough this little country. Veined Crystal Glass is considered to be one of the top types of glass quality wise.
There have been many attempts to recreate it during the subsequent centuries and even now there are magical laboratories and special craft workshops dedicated to this task. So far no success, although many other glass types have been developed over the years and have found their use in fashion, industry, medicine and in various types of magical rituals. Labradorite glass is the only one who came close, but it is still inferior.
To this day, the origin of Veined Crystal Glass remains a mystery. Too bad those mirrors are not good at gazing into the past. It is believed that the process of making them had some type of crystals or semi-precious stones added during the batch processing system, the it was formed and re-formed repeatedly into glass panels, which was followed by an internal treatment - possibly of some magical influence - before it was annealed. Coating of this glass has been broken down into chemical components and is used on other types of scrying mirrors and is probably the only piece of the puzzle that has been successfully deciphered.