just had a look at my three 'bullets', and they all show, to a greater or lesser extent, these lines which appear to start at the top and run down thru the lens. Most can be felt on the inside only, but on one example the line can be detected on the outside, just. They vary from being almost impercetable to blindingly obvious - although on my pieces certainly none is a fracture. My colours are clear, teal (?) and citrine. From what I can see, there appears no disturbance of the glass within its thickness.
Think I would have to discount Cathy's comment that these.....'might suggest a shear mark?'
- but what would help is if someone can state how the internal cavity is produced - i.e. piston plunger - compressed air etc., because I feel that is the source of these marks - in other words they are being transferred from some part of the moulding process, in this instance.
John has commented, quite rightly, on the extent of the finish quality on Sko Union pressed glass, and I notice surprisingly that whilst two of mine have the mould seams on opposite corners (as you would expect), my citrine piece appears to have been fire polished to the extend that these have been removed completely.
Nice idea px - to standardize these faults such as flea bites, mould marks etc.etc.. but you're on to a loser - too subjective - can't see people ever agreeing on what might constitute the size of a flea bite or whether something was an annealing mark or something else - just look at ebay
For what it's worth I can see the marks on the amethyst 915/200 piece, and this is typical of how the mark appears on my pieces.