Opal

In 1910, Harry Piers was asked to identify an unusual-looking mineral sample from New Ross. It turned out to be opal, a gemstone rarely found in Nova Scotia.

Piers, who was curator of the Provincial Museum (now called the Nova Scotia Museum), was often asked to identify mineral samples because of his expertise in geology. So, prospector Charles Keddy sent him the stone after finding it in a quartz vein on land owned by Amos Gates, between New Ross and Lake Ramsay, Lunenburg County.

The opal was milk-white, according to Piers, “with rather feeble internal reflections or glows of a delicate vinaceous-pink (pale yellowish pink) colour, when turned about in a strong light.”

Keddy, who played a role in the discovery of tin and other minerals in the New Ross area, had a number of other opals from the same quartz vein, some of which were “handsomer specimens,” according to Piers. They were various colours, including reddish-brown, yellow, milky-white, brownish yellow and opaque.

Opal is rarely found in Nova Scotia but occurrences of it have been discovered from time to time. Abraham Gesner wrote in “Remarks on the Geology and Mineralogy of Nova Scotia” (1836) that opals were found on Partridge Island, Cumberland County. Henry How wrote in “Mineralogy of Nova Scotia” (1869) that opal had been found at several locations, including an opal from Beech Hill near Kentville, Kings County, that had been sent to a jeweller in Halifax, Julius Cornelius, who cut and polished it to produce stones for rings.

Opal is formed from a solution of silicon dioxide and water. As water runs down through the earth, it picks up silica from sandstone, and carries this silica-rich solution into cracks and voids, which are caused by natural faults or decomposing fossils. As the water evaporates, layer upon layer of microscopic silica spheres are formed because particles of silica spontaneously adhere to other particles which form around it. This cycle repeats over very long periods of time, and eventually opal is formed.

An opal might display a single color, several, or all the colors of the rainbow. Precious opal exhibits the phenomenon known as “play of colour,” which is produced by the diffraction of white light through the spheres of silica.

When white light waves enter the top of an opal, they bend and bounce around inside it, through all the microscopic spheres and the gaps between the spheres. This splits the white light into all the colours of the spectrum, and the light eventually bounces back out the top of the stone, at which point we see the colours.

Opal is the only gemstone known to naturally diffract light this way.

Common opal does not display play of colour because the diameter and spacing of the silica spheres do not diffract the wide range of colours. Many opals can only display blue colouring, for example.

As with many gemstones, some believe that opals cause good luck and have mystical properties. However, unlike most gemstones, opals have also had a reputation for causing bad luck.

A number of stories and legends gave opal its bad reputation. A victim of the Black Plague is said to have worn an opal whose colour turned dull after she died. Another story says a Spanish king gave a cursed opal to his wife and she subsequently died of a mysterious disease. The king then gave it to his grandmother, sister and sister-in-law who each died in turn. Eventually, the king himself wore it and he, too, passed away.

One of the worst blows to opal's reputation was the 1829 novel "Anne of Geierstein" by Sir Walter Scott, in which an opal changes color with the heroine's moods. When her opal is eventually touched by holy water, it discolors. She is accused of being a demon and dies shortly after. The public was so affected by the best seller that the opal market actually crashed, and prices dropped by 50 percent. It took many decades for opal demand to recover.

It is also said that diamond traders and jewellers spread rumours about opal’s bad luck because opals were competition.

Queen Victoria did much to rehabilitate opal’s reputation during her reign. She loved them and her influence on fashion led to a resurgence in opals being used in Britain and around the world.

Harry Piers (1870-1940) was born in Halifax and became curator of the Provincial Museum in 1899. While he had a range of interests and was widely considered an expert in ornithology (birds), the Provincial Museum’s early collections were largely focussed on mineral samples and Piers became an expert in geology. He was often asked to analyse and identify rock and mineral samples and was sometimes sent to inspect mines – a particularly difficult task for him since he had a phobia of going underground, according to historian Eileen Mak.

He was also tasked with running the Mines Building at the Provincial Exhibition where, each year from 1902 to 1917, he arranged a show of the economic minerals of Nova Scotia. In order to advertise the province’s mineralogical potential more widely, the government sent him and the display to the Jamestown Tercentennial Exposition in Virginia (1907) and the Industrial Exhibition in Toronto (1908).

In addition to his curatorial responsibilities, Piers served as librarian of the Provincial Science Library and as Deputy Keeper of the Public Records of Nova Scotia from 1899 until 1931, when the Public Archives of Nova Scotia opened.

Nova Scotia does not have a history of commercial mining for gemstones but there are many that can be found, and there are many great places in the province for rockhounding. Small-scale gathering of gems is done to collect or sell them or to turn them into jewelry.

Australian opal showing "play of colour." Thanks to Dpulitzer, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons