780-797 Costantine VI Miliaresion 2,06 gram and 20 mm Sear 1595 I bought it from a reputable auction/dealer. Look at the yellow circles I have made: I just want your opinion: do you think that they are casting pearls?
I'm not familiar with these coins, so take what I say with a grain of salt. What you have highlighted (and other area on the coin) appear to me to be casting "pearls". Not knowing anything about the coin, I would not have made the purchase. I hope I am wrong.
The overall fabric of the coin doesn't look cast. I'd be more inclined to believe the "pearls" are due to die rust.
When I look at how the cross and letters of the obverse meet the field, I see a nice, sharp contact, which leads me to believe it's not a cast copy.
I asked in Forvm for some few years ago about a similiar problem with a bronze coin of Heraclius in which I thought was a cast due to the pearls at the top of Heraclius's crown: But those above were NOT cast pearls as an user in Forvm concluded something similar with die rust. Here is a 100% fake miliaresion of another emperor with casting pearls (I don't remember where I got that foto from)
Die rust happens. It's not uncommon to see an occasional bump/pearl or two on a genuine coin. So how can you tell of cast or not? There need to be at least another of these flags such as underweight/overweight out of specs, soapy legends, unatural weakness (lack of detail in the portrait/design that seems unatural given the level of wear), or polished rim/ cast line running across rim. Another diagnostic from the rim area is an edge crack that is substantial enough that it should be running across the rim, but somehow doesn't and just dies at the rim (as if it's been filled up ). Here's an example of genuine bumb/pearl caused by die rust. To the left of Asclepius (right next to his face) you see an unatural raised area. Now you could say cast because of that....but it is really die rust. The coin is in the right range of weight/diameter, the legends are sharp, design is sharp and looks struck, the rim has a crack going all the way through it and no signs of any polishing or gate marks, etc. It is not uncommon also to find genuine coins with pitted surfaces due to corrosion. But that is different from bubbles in the mold of a cast. if you can't tell the difference by looking at a photo then I suggest you get an electron microscope and look under 20x magnification. The difference between naturally occurring corrosion and something nefarious will be obvious to you once you look at two or three examples of each. Corrosion is very irregular in appearance, while the bubbles of a cast will be very uniform/smooth in appearance.
The very noticeable roughness in the "wreath" border also made me think die rust at first glance. If they polished off the rusted surface of the dies only the deepest divots would be left as seen in the fields, whereas the fuller effect of the rust remains visible in the recessed portions of the die which the border seems to display. Hopefully it's legit!
There are a few similar dots on the reverse of this coin. I examined it under the microscope and it is unquestionably struck: Your obverse in particular looks AOK so I wouldn't worry.
