Browsing around on eBay I see lots of specimens of semi-precious stones that are being sold stuck to some other, less precious/interesting base material.
This cinnabar, for example, or this emerald that appears to be smothered in a nasty piece of quartz. That’s a nice looking emerald in the rough; too bad you can barely see it.
Why don’t the sellers extract the gemstone from the larger stone and sell it unfettered by the unattractive rock that clings to it, almost tumor-like? Wouldn’t the emerald by itself fetch a better price?
Regardless of what the listing says, the “emerald” is definitely not a gem quality stone. It’s really just an example of a green beryl. Yes, true emeralds are “really” clear green beryls, but it’s the “clear” factor that makes all the difference. The top dollar gemstone quality emeralds are as clear as glass and have a warm, deep green color. This milky stone is an emerald wannabe at best.
People who do this for a living know the market. Specimens like this with minerals embedded in a matrix are often more valuable to collectors than the same stone would be to the jewelry market.
You see them offered this way because that’s how they are likely to bring the most money.
Because that’s of no interest to most collectors. If all we wanted was a shiny bauble, we could just as easily get a synthetic.
Most of us collectors like the setting of the mineral in matrix, it shows the provenance and is often more aesthetically pleasing (both those examples are, to me).
Not that one, no. It’s not really gem-quality at all.