Grandidierite is all about the rarity hype. It WAS rare at one time (5th in the rarest gemstones list I believe) - but a new deposit was found around 2017, which has made it far more commonly available. It is no longer anywhere near as rare as it was - but Gemporia still play on the 'top 5 rarest gemstones' line of old that is no longer relevant today.
There are now many more stones that are FAR rarer than Grandiderite - to the point where they're almost impossible to get hold of. Benitoite, Painite, Taaffeite, Jeremejevite, Pezzottaite, 'proper' Bixbite (not the heavily included 'Rhyolite with Bixbite inclusions' that Gemporia were flogging as Bixbite a few years ago, etc to name just a few.
If they had brought Grandidierite to air ten years ago, then yes, it would have been a really big deal simply because of it's rarity - but these days? Meh, it's just another murky greenish-blue heavily included stone that is available in mass quantities.
As for Paraiba - just to be clear, heat treatment doesn't mean that its not a 'real' Paraiba. Heat treatment is probably the most acceptable treatment out there. Unlike other treatments, it doesn't add anything artificial to the stone. Heating simply helps to make a stone clearer by dissolving some inclusions and boosting its colour slightly in the process. A stone is heated naturally underground anyway - so heating simply extends a treatment that would have happened naturally anyway underground.
What makes a Paraiba a 'true' Paraiba is two things:
a) Copper content
b) A specific colour.
To be called a Paraiba Tourmaline, the stone MUST contain copper - and it MUST fall within a specific shade of bluish-green or greenish-blue.
If it is Paraiba coloured but does not contain copper, then it is simply Tourmaline. Likewise, if it contains copper but is too light in colour or too dark in colour, then it is also not a Paraiba Tourmaline.
So long as it meets those criteria, then it's a 'True' Paraiba whether its heated or not.
