20x12x8mm 13.8 cts Ruby loose cut faceted natural 894A

Product Details

  • 20x12x8mm 13.8 cts Ruby loose cut faceted natural 894A
  • 894A
  • Ruby
  • $650.00 inc. tax

  • Units in Stock: 1

20x12x8mm 13.8 cts Ruby loose cut faceted natural 894A Summary

20x12x8mm 13.8 cts Ruby loose cut faceted  natural  894A
 
 

Corundum (aluminum oxide)

Types/Color:

Padparadshah – Strong yellow, orange-pink to hot pink.

Ruby – Red to dark pink. Usually has a hint of violet.

Sapphire – Natural corundum is commonly thought of as dark blue, but it occurs in many other colors such as yellow, green, pink, colorless and purple.

Mohs hardness: 9

Refractive index: 1.766-1.774

Critical angle: 34.5°

Specific gravity: 3.99-4.0

Cleavage: None

Fracture: Uneven, conchoidal, splintery.

Dispersion: .Moderately high (018)

Heat sensitivity: None

Pleochroism: Dichroic.  Darker colors usually show stronger dichroism.  Natural blue: distinct (dark blue to greenish-blue); Natural green: weak (more or less yellow); Natural orange: strong (orange to yellow-brown or colorless); Natural purple: distinct (purple to pinkish); Natural ruby: strong (deep red to yellowish-red); Natural yellow: weak (yellow to light-yellow).

Birefringence (double refraction): Weak (.018)

Crystal structure: Hexagonal (trigonal), dipyramidal

Treatments: Heat treating to reduce silk is standard.  Glass-filling voids in rubies is not considered an acceptable treatment.

Cutting: Corundum cuts and polishes at varying rates on different facets.  Dont cut with a bonded lap at any finer grit than 600, otherwise an orange peel effect will make polishing a nightmare.  Pre-polish with 8,000 grit on ceramic, zinc or copper lap helps speed up final polishing immensely.

Polishing: Ceramic with 100,000 or 200,000 diamond spray, or zinc lap with 50,000 or 100,000 diamond.  BATT can be used as a polish lap, but is a little soft for corundum.

Comments: Orient for best color and yield.  Corundum cuts and polishes differently on different facets.

 

Related Products

Burma Ruby Loose  Facet..

Burma Ruby Loose Facet..

Burma Ruby Loose Faceted .50 ct 6x4x3mm Loose natural X103 100% real not man made but genuine from the...

Ruby Loose Faceted .50 ..

Ruby Loose Faceted .50 ..

.50 cts 6x4x4mm Loose natural Ruby W675 Certified 100% real not man made but genuine from the earth gemstone....

Burma Ruby Loose facete..

Burma Ruby Loose facete..

SOLD out of stock Burma Ruby set 7.5mm 2.2ct and 2.1 ct 4.5 tcw s949 there are 2 stones in this lot diamond...

Ruby Masonic replacemen..

Ruby Masonic replacemen..

Ruby Masonic replacement ruby for rings for sale 12.5 tcw 12x9mm U579 There are 6 stones in this lot...

Ruby Masonic replacemen..

Ruby Masonic replacemen..

Ruby Masonic replacement ruby for rings for sale 5.8 tcw 14x12mm U577 There are 4 stones in this lot...

Sign Up for our Newsletter