Testers can and do show white sapphire as diamond but they are heavier than diamond and usually cut differently, the Hf process works great to help identify czs as they become hazy but will leave white sapphire and diamond shiny, remember not all diamond is of great quality so it's the surface that allows identification but it takes experience to pick the diamonds and leave only czs and sapphire behind.
Smoked stones and badly marked stones are easy to miss identify and broken stones can have little value unless large and of good quality.
Welcome to the world of stone dealing its about as easy as understanding the whole of refining and recovery of precious metals but it can add a little to the pot.
While people look only to diamonds for value coloured gems can and do have a value but finding buyers is really hard as that whole world has no written rules or price guides, large,good colour, clear and well cut sapphire, rubies, emeralds etc can and do cost thousands. While small commonly used stones can be cents large good quality stones can be very expensive, high quality sapphire is rising in price monthly and many other stones are doing the same, in truth diamond is common, good quality rare, the same goes for most stones.
Finding good honest buyers is hard but they do exist.
