Rating Topaz: The Ultimate Guide

London Blue Topaz Meaning

Since London Blue Topaz doesn’t occur naturally, its traditional meaning is derived from Sky Blue Topaz (the only natural and rare blue form) and topaz in general. London Blue Topaz is known for its calming properties, soothing nerves, and healing negative emotions. As per the Vedas, blue topaz serves as a valuable aid in meditation.

Topaz is one of November’s birthstones, sharing this honor with citrine due to the yellow varieties of topaz. However, blue topaz has become a favored alternative in recent times. The serene blue of blue topaz is reminiscent of aquamarine, although their hues differ slightly.

Topaz Grading Criteria

Like other gemstones, London Blue Topaz varies widely in quality. The primary factors influencing its grading and value are color, clarity, and cut. Remarkably, topaz is abundant, so the value isn’t significantly dependent on carat weight. Thus, a two-carat stone of the same quality only costs as much as two one-carat stones.

Color

For London Blue Topaz, color holds the utmost importance. ‘London Blue’ refers to a specific shade that is narrowly defined as a medium or dark grey blue. It is neither the light ‘sky’ blue (which is natural and pastel) nor the medium blue ‘Swiss’ blue (which lacks the grey undertone). The presence of a grey tone is critical; any greenish tinge can reduce its value. Ideally, the color should be deeply saturated without lighter spots or pale steel grey hues.

Clarity

The treatment process for London Blue Topaz often enhances its clarity by masking inclusions with darker colors and removing them during subsequent heat treatment. These enhancements are permanent and widely accepted in the jewelry industry.

Inclusions are any impurities that affect a gemstone’s transparency, manifesting as specks, cracks, or feathers. Faceted London Blue Topaz typically lacks visible inclusions, although they may be present in rough crystals, as depicted below.

Crystals

Smaller mineral crystals trapped during the growth of the topaz crystal.

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Needles

Long and thin crystal inclusions that resemble needles.

Cleavage Breaks

Topaz, like diamonds, can break along certain planes. When these breaks do not cause the crystal to fall apart, they’re called cleavage breaks.

Feathers

These are stress cracks within the crystal resembling feathers. Other types of inclusions can occur but are less frequent.

Cut

The cut of a London Blue Topaz isn’t as critical as it is for diamonds or sapphires, except to ensure the facets are well-crafted and the gem has a brilliant polish. Generally, cabochons are less labor-intensive, making them a cheaper option compared to faceted stones.

Step Cuts

Featuring fewer facets placed along parallel lines, the emerald cut is popular for London Blue Topaz, often used in engagement rings. Other step cuts include asscher and baguette cuts.

Brilliant Cuts

Designed to enhance brilliance, these cuts feature kite or triangle-shaped facets and can include curved surfaces. Popular choices include round brilliants, which are often paired with rose gold for a stunning contrast. Brilliant cuts can also be found in oval, marquise, pear, and heart shapes.

Cabochon

Perfect for London Blue Topaz with lower clarity ratings, the cabochon cut features a rounded top with a high polish. It’s designed to showcase the gemstone’s color while incorporating any inclusions into its unique appearance. Often used in sterling silver rings, cabochons offer an affordable way to add some shimmer.

London Blue Topaz Grades

The grading system for London Blue Topaz isn’t standardized, but it often ranges from AAAA to AA or even B. The ideal London Blue Topaz boasts a deep blue-grey color, minimal to no visible inclusions under magnification, and a well-executed cut.

AAAA

A top-grade AAAA London Blue Topaz exemplifies ideal specifications without any additional treatments.