also read here

hmmm, wonder how much the new space diamonds will cost? I want one =)

If Earth based diamonds are pure 'carbon of carbon' then what are these?

There is no purity in nature. Any mineral always contains an admixture of elements in its crystal structure (isomorphism). Small amount of (1/10e6 or less) of chromatic elements (Fe, Mn, Co, Cr etc.) changes color from colorless to green, violet, red, whatever.
Also, any mineral has gas inclusions - outside its crystal structure like ice contains air. This gas is said to contain unusual for earth conditions isotopic characteristics.

That's good to know, but again why are 'these' considered 'diamonds' at all? A dimanond can start as a lump of coal and then thru extreme heat and pressure becomes a diamond, yes?

These 'Black diamonds' look like a porous lump of coal to me...

The difference between diamonds and coal is in structures and formation mechanisms. Coal is amorphous. It is formed in sedimentary conditions. A diamond has a cubic crystal syngony. it occurs in very specific magmatic rock, kimberlite. As there is no any coal in magmatic rocks, a diamond is formed of other source of C, possibly methane (CH4). There is no a solid theory on diamond formation mechanism, but it is likely to form in the mantle under tremendous P-T conditions. You found the carbonado to look like coal because of its very fine-grained constitution (grains are less than 0.1 mm).