15.60 Ct Pear Diaspore     VS     13.90 Ct Emerald Kyanite

Diaspore

Pear

15.60 Carat
21.89 x 13.20 mm

Kyanite

Emerald

13.90 Carat
15.78 x 11.68 mm
Stone Type
Diaspore Kyanite
Stone Shape
Pear Emerald
Stone Weight
15.60 carat 13.90 carat
Length X Width
21.89 x 13.20 mm 15.78 x 11.68 mm
Length / Width Ratio
1.66 1.35
Approx Face-up Area
210.75 mm² 171.49 mm²
Approx Volume
917.56 mm³ 755.44 mm³
Mineral
Diaspore Kyanite
Chemical Formula
AlO(OH) Al2SiO5
Crystal Structure
Orthorhombic Triclinic
Hardness
6.5 - 7 4.5-7
Specific Gravity
3.4 3.68
Gram weight
3.120 gm 2.780 gm
Ounces weight
0.1101 ounces 0.0981 ounces
Refractive Index
1.70 - 1.75 1.710 - 1.735
Cleavage
1,2;2,1 Perfect
Luster
Vitreous Vitreous,Pearly
Birefringence
0.048 0.012 - 0.033
Wearability
Good Very good
Birthstone
Diaspore is not an official birthstone for any month Kyanite is not an official birthstone for any month

Diamond Guidelines 4Cs and More

Before purchasing a diamond, one should make sure it looks its weight. It's important to understand that carat weight does not equal face-up size.

Two diamonds of exactly the same weight (and shape) can vary quite considerably in face-up size. This depends on the proportions of the cut (e.g., deep cuts will face up smaller)..

Face-up area is a measure of the size of the diamond when viewed from the top view.

It tells you how big the diamond is at the girdle plane. It's important for a diamond to have sufficient face-up size for its carat weight

Diamond prices vary greatly as they depend on the combination of unique characteristics (4Cs - Cut, Color, Clarity, and Carat). For best value, it's important to choose the combination that will reduce the price without having a negative impact on appearance.

You also need to consider some of the following points as well

  • Strong blue fluorescence.
  • Fair or Poor symmetry.
  • Extremely thin or extremely thick girdle.
  • Inclusions visible to the naked eye.
  • Diamond Certification.

Blue fluorescence can have a positive, negative, or zero effect on a diamond. Diamonds in the lower color range (H or lower) can benefit from it, as it can make them look whiter, more colorless. On the other hand, strong fluorescence can cause a stone (especially in the higher color range D-G) to appear hazy or milky under certain light conditions. One of the biggest benefits of fluorescent diamonds is that they generally cost less.

Blue fluorescence can be found in 35% of naturally mined diamonds and it makes the stone glow under UV light. Outside of UV lighting environments, there are no visual differences between fluorescent and non-fluorescent diamonds.

However, there exists a big difference in pricing between these diamonds. In the industry, diamonds with fluorescence are usually traded at a 10-15% discount and can go as high as 25% for higher colored diamonds.

GIA grades fluorescence as None, Faint, Medium, Strong, and Very Strong.

There are Many Laboratory Available which provides certification for Gemstones.

  • GIA - Gemological Institute of America
  • AGS - American Gemological Society
  • HRD - The Hoge Raad voor Diamant
  • IGI - International Gemological Institute
  • EGL - European Gemological Laboratories
  • GSI - Gemological Science International

*Different certification labs give different results

Piecut Diamonds are set of small Diamonds, which are cut & polished with Precised Measurements to look like a Single Solitaire diamond which can save 80% to 85% from Solitaire Single Piece Price.

Shapes of Pie Cut Diamonds.

  • 9 Pcs Emerald
  • 9 Pcs Round
  • 4 Pcs Round
  • 3 Pcs Heart
  • 4 Pcs Oval
  • 4 Pcs Pear
  • 4 Pcs Marquise
  • 5 Pcs Star

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