FB.
Brilliant_Rock
- Joined
- Jun 29, 2009
- Messages
- 764
Not all of the Pricescope members are fortunate enough to live in North America, so we have to often "screen" diamonds from only partial information. As one of these less-fortunate people, I find it frustrating - both from the lack of information provided by vendors and from the tendency of people to demand images (which aren't easy to obtain outside the US) before they'll even dare to make a comment on a stone.
But I am confident that there must be ways to "screen" out stones, to try to dramatically improve the chances of a good stone, even if information is patchy.
For example....
It seems as if stones with Excellent polish have a high chance of being a good performer. Excellent symmetry also seems to have a small positive effect.
Perhaps because the cutter felt that the stone was worth the extra effort, he spent the time on a higher polish.
It also seems as if stones with partial information - such as table and depth - that fall within AGA's 1A-1B cut grade, also have a higher-than-average chance of being a winner.
Perhaps because the general proportions are conducive to a good performance.
It also seems as if stones that are a noticeable amount (e.g. 5%) above a carat-weight boundary, have a higher chance of being good performers.
Perhaps the cutter had enough extra weight to play with to make an attractive stone without falling on the wrong side of a magic weight boundary line (e.g. 0.5ct, 1.0ct).
So, I reckon that if only partial information is available for an unseen online stone, the odds of picking a good one are improved dramatically by looking for:
Polish: Ex
Symmetry: VG-Ex
Table: within AGA grade 1A-1B
Depth: within AGA grade 1A-1B
Girdle: within AGA grade 1A-1B
Carat weight: 5% or more above a magic weight number
Bear in mind that I'm especially thinking of ways to determine whether it's worth travelling many miles to view a stone, or whether it's worth having a stone shipped for personal inspection/approval/rejection before buying.
What do the PS members think?
But I am confident that there must be ways to "screen" out stones, to try to dramatically improve the chances of a good stone, even if information is patchy.
For example....
It seems as if stones with Excellent polish have a high chance of being a good performer. Excellent symmetry also seems to have a small positive effect.
Perhaps because the cutter felt that the stone was worth the extra effort, he spent the time on a higher polish.
It also seems as if stones with partial information - such as table and depth - that fall within AGA's 1A-1B cut grade, also have a higher-than-average chance of being a winner.
Perhaps because the general proportions are conducive to a good performance.
It also seems as if stones that are a noticeable amount (e.g. 5%) above a carat-weight boundary, have a higher chance of being good performers.
Perhaps the cutter had enough extra weight to play with to make an attractive stone without falling on the wrong side of a magic weight boundary line (e.g. 0.5ct, 1.0ct).
So, I reckon that if only partial information is available for an unseen online stone, the odds of picking a good one are improved dramatically by looking for:
Polish: Ex
Symmetry: VG-Ex
Table: within AGA grade 1A-1B
Depth: within AGA grade 1A-1B
Girdle: within AGA grade 1A-1B
Carat weight: 5% or more above a magic weight number
Bear in mind that I'm especially thinking of ways to determine whether it's worth travelling many miles to view a stone, or whether it's worth having a stone shipped for personal inspection/approval/rejection before buying.
What do the PS members think?
300x240.png)