Pink Legacy could set auction record

A rare pink diamond weighing in at almost 19 carats, one of the largest of its kind ever auctioned, could sell for between $30-50m


Once owned by wealthy Oppenheimer family

FOUR Cs OF QUALITY
1 Colour: Fancy Vivid Pink
2 Clarity: VS1
3 Cut: Emerald
4 Carat weight: 18.96
14.47mm
Type IIa: Most chemically pure, with exceptional optical transparency
Pre-auction estimate: $30m-50m


GRADING METHODOLOGY
1 Colour: Graded from perfect stones (no hue) to yellow/brown, or even rarer “fancy” colours:
D E F GH I J K L M N O P Q R S T U V W X Y Z Fancy
Fancy: Stonger yellow or brown hue than “Z” or exhibit different colour, such as Vivid Pink

2 Clarity: Refers to absence of inclusions and blemishes. There are 11 specific grades:
FL IF VVS1 VVS2 VS1 VS2 SI1 SI2 I1 I2 I3
Very Slightly Included: Minor blemishes visible using 10x magnification

3 Cut: Diamond’s sparkle depends upon cut (shape) and how well facets interact with light
Round Oval Marquise Pear Heart Emerald
Emerald: Cut-cornered rectangular step cut 
Polish and symmetry: Very good

4 Carat weight: Measures size – one metric carat = 200mg
Size examples (width):
0.25ct	0.5ct	1ct	5ct	18.96ct
3.2mm	3.8mm	4.8mm	8.9mm	14.47mm

Rarity: Stone is unparalleled – Fancy Vivid Pink diamonds over 10ct almost unheard of


HOW DIAMONDS ARE MADE
Under extreme pressure and high temperatures deep within Earth’s mantle, carbon crystallises to form diamonds

About 150km deep

Graphite (layered form of carbon) compressed into new atomic arrangement – diamond

Deep-source volcanic eruptions carry diamonds to surface in rock channels

Mantle


Sources: Christie’s, Gemological Institute of America, Reuters 
Pictures: Christie’s 
© GRAPHIC NEWS