Or better still, from Gem Select where the prices are lower on most stones (not all - but most), the quality of the cut is usually better, and you actually get the stone you see in the photo - unlike Gem Collector, where I've occasionally bought stones that look good on screen, but I've had a different stone sent to me, on the same item code, that is washed out or badly windowed.
They used to say that they didn't pick the best stones out to show on-air - but I'm not convinced these days - particularly when the presenters get the stone out of a bag that says "studio sample" on it.