Isn't the copper blue dial material aventurine "goldstone"? My father brought this model out of the safe to show me about a year or two ago so my memory might be fuzzy. The thing about the gen dial is that the copper + whatever other "impurities" that form the stardust are actually more "suspended" inside the dial material instead of sitting on top (some copper impurities may be very close to the top, but that's more up to chance). The gen photos on the internet I've checked don't really make it obvious at all since they all look like they sit at the top, but irl that is absolutely not the case. The subtle differences in depth creates a very powerful effect...as if you have a mini galaxy in the palm of your hand.
Since none of the pictures online for the gen saxonia copper blue seem to be able to capture the effect...I found a more suitable example from this spherical goldstone photo. The effect is far more pronounced because you're not looking at a flat dial with limited depth, but this is generally a better idea of what you should be looking for.
The rep dial is sad because it's either low quality goldstone or not goldstone at all, but based on the close ups from trustytime...it seems like they put metal foils(?) of differing shades on top to simulate depth so I'm more willing to bet on the latter guess. The rep dial also looks incredibly opaque, and not quite as reflective with the super mini hint of translucency that the gen has. I'll wait for your review, and see how it stacks up, but I just felt like clarifying the issues I see based on my experience
These are mostly impressions from old...potentially fuzzy memories, and research into the dial material so take my impressions with a grain of salt since I don't have liberal access to see the gen.
https://geology.com/gemstones/goldstone/ <- a short primer with good close up photos of aventurine glass and goldstone with some caveat emptors when buying goldstone. It really isn't something that lends well to photos so even the one I showed below doesn't fully capture the "aventurescence." (the Lange dial has a lot of this quality so it's naturally on the higher end of aventurine quality)
https://www.etsy.com/search?q=goldst...der=price_desc The most expensive goldstone pieces here are enormous...sculpted...or paired with a hefty helping of precious metals. Goldstone really isn't supposed to be THAT expensive. It's really just more novel for watchmaking, hence the significantly higher price by ALS compared to regular saxonias.
https://www.spiritrockshop.com/Goldstone.html the photo below is from this shop and costs a whopping 29 usd.
Aventurine "Goldstone" Sphere (Left Photo) and Replica Saxonia Copper Blue Dial (Right Photo)