Hello Tomato
As I said, I do not know the incidence of VD in core other than to say I know it is rare.
Seeing diamond in core is statisticly rare but does NOT indicate grade of a pipe. It could be a rich phase (one of many), it could be surface enrichment, (see Aber 418) it could be sheer statistical luck as diamonds are not distributed uniformly. It is suggestive of good potential but that is all.
In so far as WSP is concerned, VD in core does not indicate a high grade pipe as no pipe has been delineated. To my knowledge they have dykes and a sill intercept so far.
A .9mm stone is not considered a macro by most well respected diamond explorers but rather 1mm and up are considered such. Some juniors refer to .5mm as a macro but this is not the preferred norm.
The ratio of macros to micros (30%+), high macro counts, the number of macros over 3mm, .5 carats/tonne + ore, and consistent diamond counts are the legitimate PRELIMINARY measures of good grade.
Obviously colour, clarity and crystal shape factor into grade valuations, but this comes a little later.
There is no one hard fast rule however as some very low grade pipes produce exceptionally large high quality gems, so we can only look at any of this data as INDICATIVE or TREND SUGGESTIVE, that is all.
Regards |
