So I called the number on the VCA site and spoke with a very nice man. I explained that a few people have experienced blue agate fading and were questioning whether the blue agate is dyed. He said he has been to the workshop where the blue agate pieces were made and it is 100% NOT dyed. They search all over the world for natural blue agate. They do not use any treated (dyed) stones in their pieces. Any color change over time would be from external factors that have been named multiple times on this thread, because agate/chalcedony/quartz is a porous stone.
There are actually pictures on page 105 of the Van Cleef Family Portrait thread of chiaoapple's collection and you can see that there are blue agate motifs with differing shades of blue. So yes, there can be color changes, but it is not because the blue agate is dyed.
There are actually pictures on page 105 of the Van Cleef Family Portrait thread of chiaoapple's collection and you can see that there are blue agate motifs with differing shades of blue. So yes, there can be color changes, but it is not because the blue agate is dyed.