Just had a listen to the webinar and a read of the thread, once...

Just had a listen to the webinar and a read of the thread, once again a good presentation and I like the approach.
Regarding Fancy colour diamonds, most mines produce around 0.1% by volume of Fancy Yellow and if you take that further to 1ct stones it is likely to be a lot less. Not including browns other Fancy colours are around 1 in 10,000 stones. It is a niche, though a tricky one just to find! There is also significant competition to purchase with the likes of Tiffany, Graf, Winston and Chow Tai Fook amongst others in this space.
Ellendale E9 Yellows are extremely marketable, as can be seen in the previous operator selling most of them exclusively to Tiffany's. E9 pipe produced on avg 11% Fancy Yellow and Blina alluvials appear to be mainly represented from this with sampling around 7% Fancy Yellow.
Naujaat looks promising as a source for Yellow/Orange also, though these stones may be more problematic than Ellendale Yellows if it proves economic.
Botswana is greenfields and the chances of finding a significant producing mine are small (though in the right area) let alone producing significant fancy colours.
Buying Fancies on market can be tricky as mentioned there are many players already bidding, so getting an arrangement with producers could provide a steady supply of Yellows, other colours are more random. Likely have to pay over market prices for supply.

There are many risks in finding/mining diamonds and currently none of Burgundy's projects are over the line, though Blina should be be a good start even if small. It's possible Burgundy's best asset isn't even in the pipeline yet! It is also good to have a competent team involved to give this the best chance of success.