Brooch – 1920s Bar Brooch
A white gold-coloured gem-set bar brooch¹ principally designed as a flat bar with one claw-set blue zircon² and two round pearls. Secured with a pin and hook clasp and employing a base-metal safety chain. Circa 1920s.
Measuring: 51.07mm x 6.95mm.
Unhallmarked: tested and valued as 9ct gold.
Scratch engraved: ‘2A70’.
Assessment of the Gemstones.
Cut: ‘zircon-cut’³ (round eight-main brilliant-cut crown over a three-tiered eight-main brilliant-cut pavilion).
Measuring: 6.09mm x 6.05mm x 4.35mm.
Calculated weight: 1.35cts.
Colour: light greenish blue (2.5B.6/7).
First measuring: 3.87mm.
Second measuring: 3.54mm.
Average colour: greyish white.
¹. Bar brooches appeared in the 1890s and immediately enjoyed a great success. In its simplest form the bar brooch was plainly set with a single diamond, but its functional shape offered the jeweller a field in which to exploit their fantasy and imagination, thus bar brooches were decorated with crescents and stars, sprays of leaves and flowers, pheasants and chat idles, swallows and flies, shamrocks and clovers (David Bennet and Daniela Mascetti 'Understanding Jewellery', 1989). After 1900 and certainly by 1910 the cuir roule and overt styling on bar brooches was replaced by the simple shape of a straight line, sometimes set with calibrated gemstones, or using white gold or platinum.
². The blue zircon was highly popular in the first half of the 20th century as an eye-catching trompe l'oeil. It's high refractive index and the strong colour dispersion endow it with an adamantine lustre and sparkling lively fire; all which make zircon the close neighbour of diamonds. (Eduard Gűbelin and Franz-Xaver Erni, “Gemstones, Symbols of Beauty and Power’, 1999).
The name zircon is said to have been derived from the word ‘zargon’, which in Arabic means ‘vermillion’ and in Persian ‘gold-coloured’. Hitherto, zircons have been variously known as ‘jargoon’ or ‘cerkonier’; the first name is said to have been derived from the Italian word ‘gaicone’, which is probably a corruption of ‘zargoon’. The sources of zircon our worldwide, the mineral being a common accessory constituent of igneous rock, but the gem quality zircons are found in more localised areas. Zircon is prolific in the gem gravels of Sri Lanka and the mineral is found in gem quality in the Mogok stone track of a Burma. The most important localities for gem quality zircon are those of Vietnam, the mining areas of which in some cases pass into the neighbouring territory of Thailand – the mines in Kha, Champasak and Palin district (Robert Webster, ‘Gems. Their Sources, Descriptions and Identification’, fifth edition, 1994).
³. A ‘zircon-cut’ is a modified brilliant facet design extensively used with zircons, thus giving the facet design its name. A third tier of facets are cut around a largish culet facet, which adds scintillation to high refractive materials such as zircon.