Georgian Imperial Topaz Natural Pearl Halo Ring

This ring evokes the pretty phase of the Georgian era. A time when jewelry matched the daytime clothes (Scarisbrick, 2007). When it communicated rank, taste, and access. There is a sense of high standing here. 

The center stone is an imperial topaz, a color that shifts between golden peach and rose. It reflects the hues that was prized in the 19th century and is still coveted today. When it is moved in the light, the stone responds subtly showcasing a variety of sunset hues. The topaz is set closed back, consistent with Georgian construction. 

Protecting the imperial topaz are original natural pearls. Their presence reinforces the refinement and luxury of the ring's overall character. 

Specification

1820s, Georgian era. Please see photo below of an example

18k gold (with 9k gold at the interior and back of the shank, see condition notes)

Natural pearls, confirmed by a gemologist. Laboratory testing was not possible due to the mounting

Imperial topaz, confirmed by a gemologist, set in a closed back foil setting. Likely not heat treated due to strong pleochroism presence.

5.17g

Condition

In very good antique condition. XRF and visual inspection confirms historic gold work limited to the interior back and small area of the shank replaced and finished by hand engraving. There is evidence of reapplied gold that also have small areas of pitted gold, structurally sound and ready for wear. 

Typical wear at the facet junctions of the topaz. Visible nacre to the pearls. Evidence of wear is consistent with age and respectful use.

Care

Limit or eliminate water exposure due to the closed foil back setting. If exposed under water, please let it air dry fully.

Resource

Similar examples of the ring’s shank can be found by “Rings: Jewelry of power, Love and Loyalty” Page 328

1820s Georgian Diamond Cluster ring (head possibly earlier)

Note on terminology: GIA notes that there is no formal standard for the term “imperial topaz,” and that usage varies within the trade (GIA). It’s been reported that historically fine topaz is sourced from Russia and Brazil. Within Brazil, high-quality material in this color range has been reported from areas southwest of Ouro Preto, Minas Gerais. A published 1822 account describes examinations of Brazilian topaz specimens reported as red in color and “perfectly transparent” (GIA). GIA further reports that red topaz represents less than 0.5% of facet‑grade material (GIA). For context, this proportion is lower than the occurrence of Type IIa diamonds.

Source (GIA): https://www.gia.edu/gia-faq-imperial-topaz and https://www.gia.edu/reading-list-imperial-topaz

Note on topaz treatment: Yellow to brown topaz colors (including gold, orange, and sherry tones) are identified as the most historically prized topaz colors and commonly grouped under the term imperial topaz (Nassau, 1985). The author notes these colors are likely to be natural (Nassau, 1985). Heat treatment for this stone is unlikely, but this cannot be confirmed since GIA does not provide such evidence. Heat treatment will alter color centers by allowing trapped electrons and defects in the crystal lattice structure to relax or recombine, which homogenizes the color (Nassau, 1985).

See other common topaz treatment below:

Colorless topaz can be irradiated into an orange brown color but are considered unstable and this technology was not available when this gemstone was cut. Nassau also explains that when orange-brown topaz is exposed to heat that it can lighten or remove the yellow brown color. Yellow and orange brown topaz with chromium can be heat treated to turn pink (Nassau, 1985). And specifically, blue topaz has been made largely commercial since the mid-20^th due to colorless topaz transforming to blue (Nassau, 1985). GIA does not offer heat detected treatment with topaz and it can be assumed that most blue commercial topaz has undergone some treatment.

Taken from the article, Altering the Color of Topaz:

References:

Scarisbrick, D. (2007). Rings: Jewelry of power, Love and Loyalty. Thames & Hudson.

Topaz quality factors. Gemological Institute Of America. (n.d.). https://www.gia.edu/topaz-quality-factor

Brewster, D. (1822). On the Distribution of the Colouring Matter, and on Certain Peculiarities in the Structure and Optical Properties of the Brazilian Topaz. By David Brewster. United Kingdom: J. Smith, printer to the University.

Nassau, K. (1985). Altering the color of Topaz. Gems & Gemology, 21(1), 26–34. https://doi.org/10.5741/gems.21.1.26