A quick overview!
Natural gemstones with no treatment = The most pricey and highly valued. You'll very rarely find these on TV shopping channels UNLESS it's a gem that doesn't have need to be treated - and these are getting less common by the day as man seems to be intervening in almost everything now. It used to be safe to say that garnets were never treated but ........... not now :sad:
Heated gemstones = True collectors may sometimes buy these, others won't. They are still harder to come by than the next category and worth less than a natural unheated gemstone but considerably more than a treated gemstone.
Treated gemstones = Treatments include BE diffusion, filling, irradiating, oiling, dying, waxing, bleaching, coating, making composites, triplets/doublets etc etc etc. This category is typical of the type of gemstone that is low cost and therefore available in bulk via TV shopping channels. They can be picked up very very very cheaply.
However, there are some treatments to certain gemstones that are accepted/expected, e.g.
- Tanzanite is usually heated to achieve the blue colour. This is a permanent, stable treatment and considered normal for this gem and NOT something to worry about. There is also very little price difference between a heated and unheated Tanzanite. So this is not something to be concerned about. However, there is coated Tanzanite on the market and that can be scratched off. There's not much of that about and I don't think the TV shopping channels stock it in any case.
- The great majority of Emeralds are oiled or filled with a substance to make the jardin less prominent. This is usual and has been happening since Egyptian times. Nothing to worry about with these BUT Emeralds are also dyed, made up of composites and various other hideous treatments. These are worthless and should not be bought! I don't know what GemsTV sell so can't comment.
Personally, I very rarely buy anything but natural and gently heated gemstones. I stay clear of heavily treated gemstones because they are altered beyond belief and NOT how nature intended them to be. This is my own personal preference BUT I fully understand that there is a market for these gems and it does make pretty gemstones available at an affordable price to people who just want some new jewellery for fun. These gemstones will NEVER increase in value or become heirlooms (mind you, most jewellery won't either)!
In terms of treatments that nobody ever speaks about:-
- Sapphires/Rubies (the corundum family). Unfortunately, unless you know where to buy, nearly all sapphires and rubies sold by TV shopping channels are highly highly highly treated. They may be BE diffused (which is a permanent treatment that takes a natural sapphire that's a horrible yucky colour, diffuses it with Beryllium and out pops a very vibrant coloured gemstone). BE diffusion dramatically affects the price. Although these are natural sapphires they are NOT as nature intended. Cracks are filled in rubies (not always a stable and permanent process) and although the gem may look okay when you buy it, 10 years down the line it may be a whole different story.
I could rant for a few years and give you tons more examples but I don't want to bore you!!! At the end of the day, you should assume that each and every gem you buy from a TV shopping channel is heavily treated and therefore will not hold it's value. If you buy with that in mind, then you'll never feel cheated later down the line.
GemsTV rely on having an enhancement page on their website and so you will very rarely hear the presenters talk about treatments. Occasionally they do, but not often.
Unfortunately this discussion is not new to this forum and every now and again we have a rant about it. If you search for "treatments" you'll probably find a number of other threads on the subject.
Hope that helps (and that I haven't depressed you too much).