I collect gemstones, both loose and set in jewellery, as an investment and because they intrigue me - the composition and evolution. I would strongly suggest that, prior to making a purchase, you ought to gather information on the gem, it's hardness, acceptable/desirable attributes, etc. Whilst the presenters know what they are talking about - they have to complete courses in gemology - the quality of gems can be quite subjective. Gems can be termed as being 'eye clean'. We all have different eyesight - short/long sighted, for example - so what appears perfect to one may have obvious inclusions, visible to someone with better vision.