VVS CONGAC TOPAZ-RICH COLOUR - 5.25 CTS [S4916]

3392

存貨單位
尺寸（毫米）: 10.000 x 9.000 x 7.000mm
重量 (cts)
Certified Gemstones: 不
類型: Faceted
顏色

SPARKLING CONGAC TOPAZ

This is a well facated natural clean topaz stone which has been heat treated to enhance the colour.

Mined in Brazil

OVAL

Grade A colour

Transulant

Grading VVS

Total weight 5.25 cts app

Size 10 x 9 x 7 mm

Topaz is commonly associated with silicic igneous rocks of the granite and rhyolite type. It typically crystallizes in granitic pegmatites or in vapor cavities in rhyolite lava flows.

Pure topaz is colorless and transparent but is usually tinted by impurities; typical topaz is wine, straw yellow, pale gray or reddish-orange. It can also be made white, pale green, blue, gold, pink (rare), reddish-yellow or opaque to transparent/translucent.

Topaz has a hardness of 8 on the Mohs scale and is the hardest silicate along with beryl (Aquamarine). The Toughness of Topaz is Fair. Topaz crystallizes in the orthorhombic crystal system, with an "Elongate Prismatic" crystal habit. Pinacoid, multiple domes and orthorhombic pyramid faces produce complex and multifaceted terminations that are well formed. Topaz has a chain-like lattice structure of irregular octahedrons. Topaz has perfect (easy) basal cleavage in one direction (in the plane perpendicular to the c-axis), with a conchoidal fracture, therefor it is a difficult stone to set without fracturing. Topaz has a refractive index of 1.610 to 1.630.

Type 1 Gemstones

The following gemstones are typically inclusion free, even minor inclusions detract from their value.

Diamond, Amethyst, Beryls(Aquamarine,Morganite), Citrine, Smoky Quartz, topaz, Chrysoberyl, Kunzite, Tanzanite, green Tourmaline, and Blue Zircon

IF	Internally flawless under extreme magnification (Very rare)
F	Flawless
VVS	Minute inclusions under 10x; invisible to the unaided eye
VS	Minor inclusions under 10x; usually invisible to the unaided eye
SI1	Noticeable inclusions under 10x; usually visible to the unaided eye
SI2	Noticeable inclusions under 10x; usually quite visible to the unaided eye
I1	prominent- moderate affect on appearance or durability
I2	prominent - severe affect on appearance or durability
I3	prominent- severe affect on beauty, transparency or durability

Type 2 Gemstones

Gemstones that normally have small inclusions that do not detract from value.

Alexandrite, Andalusite, Iolite, Peridot, Rhodolite, Ruby, Sapphire, Spinel, Tourmaline, Garnet, Amethyst, Red Zircon, Tsavorite; Blue, Orange, Purple, Fluorite.Yellow and Parti-colored Tourmaline

F	Flawless
VVS	Minor inclusions under 10x; usually invisible to the unaided eye
VS	Noticeable inclusions under 10x; often invisible to the unaided eye
SI1	Obvious inclusions under 10x; visible to the unaided eye
SI2	Obvious inclusions under 10x; very apparent to the unaided eye
I1	prominent - moderate affect on appearance or durability
I2	prominent - severe affect on appearance or durability
I3	prominent - severe affect on beauty, transparency or durability

存貨單位
尺寸（毫米）: 10.000 x 9.000 x 7.000 mm
重量 (cts)
Certified Gemstones: 不
類型: Faceted
顏色