New Article by Bruce Harding - Dimensioning Diamonds

[coati]

Please visit this new article by Bruce Harding to learn more: Dimensioning Diamonds

There have been inconsistencies and vagueness about how diamond dimensions are defined.
This clarifies the terms and differences and suggests better alternatives. Due to QWERTYism* none of this will change. (* Explanation why first line of typewriter is so: “It’s that way because it always was that way.”)

Thanks, Bruce, for your contribution to the Pricescope Journal.

 

[Karl_K]

I smacked my hand 3 times and still cant stop myself from posting....
qwerty came from separating the most common keys to prevent mechanical typewriters from jamming when someone was typing faster than the hammers could return.

I don't have an opinion on how the facet % are measured as long as its consistent or labeled it don't bug me.

 

[heididdl]

Would someone please spell this out in lay terms I am interested an don't grasp this at all.

 

[Karl_K]

Would someone please spell this out in lay terms I am interested an don't grasp this at all.

There are 2 different ways to measure star % and lower girdles/halves he is making a case for one being better than the other.
one way for lgf%:
Along the facet, how far does it extend down the diamond compared to the end full length.
Other:
When looking the diamond from the side how far down does facet go measured as a ratio to pavilion depth.

 

[teobdl]

Would someone please spell this out in lay terms I am interested an don't grasp this at all.

There are 2 different ways to measure star % and lower girdles/halves he is making a case for one being better than the other.
one way for lgf%:
Along the facet, how far does it extend down the diamond compared to the end full length.
Other:
When looking the diamond from the side how far down does facet go measured as a ratio to pavilion depth.

His rationale for using this alternative method is that it can be applied to cuts including the modern round brilliant but also ovals, pairs, and cushions. The current method can only be used for MRB's.

 

[beryl]

Karl: I know about the reason for 'qwerty' but 'qwertyism' is used in government circles (I am told) to say "it's that way because it is - don't ask" about any subject where the reason for something is used blindly by tradition.
. Do you have the book "QWERTY"? Very interesting.

 

[Karl_K]

Karl: I know about the reason for 'qwerty' but 'qwertyism' is used in government circles (I am told) to say "it's that way because it is - don't ask" about any subject where the reason for something is used blindly by tradition.
. Do you have the book "QWERTY"? Very interesting.

Nope haven't heard of the book.

I know it is used at times to mean that but it is one of my pet peeves, its not like we don't know why it was done that way and still done that way(hugs cost of retraining workers and alternative layouts have been commercial flops).

 

[beryl]

Teobdl:
. Thanks for your comments clarifying my notes to other readers.
. I add my preference of 'slope' for facet inclination; it is specific and more meaningful than 'angle'. The recent GAA article uses it a lot.
. I also prefer 'break' for secondary facets (from FGA course?). Diamond cutters use 'halves' but GAA article refers to them as 'girdles', as do most colored-stone cutters - what then would they call the ones on a faceted girdle?
. I started cutting before I was aware of any 'standard' terminology and dimensioning of faceted gems. It seems there isn't any.