Details: Scottish Agate, Topaz, 9ct Brooch, William Henry Leather ±1900.
Dispatches from a small business in Amsterdam, The Netherlands.
Design Era: Late Victorian (1885-1900).
Dimensions: 80 x 11 mm.
Weight in grams: 11,9.
Condition: Good condition – used with some signs of wear.
During the Late Victorian or Aesthetic period (1885-1900), jewelers used diamonds and feminine, bright gemstones such as sapphire, peridot, and spinel. Star and crescent designs as well as elaborate hat pins were also popular. Some scholars believe the aesthetic era began sooner, in 1875, and ended as early as 1890.
The name agate is derived from the Achatus river in Sicily (now named the Dirillo river) where large amounts of this gem were discovered as early as 300 BC. During the Gallic wars, agate deposits were discovered along the Nahe river (a tributary to the Rhine) in Germany. The gem-cutting facilities set up there by the Romans survive to present day and, although the deposits are now depleted, Idar-Oberstein – on the Nahe river – is still the major lapidary center of Europe. Today the agates cut there are imported from Brazil and other locations.
Topaz is a gemstone which, throughout history, has shared its name with all other yellow gemstones. It was not until the mid 18th century that the name was assigned to the aluminum fluor-silicate that is uniquely topaz. During the 16th century Cellini described a (most probably) yellow sapphire as "topaz". Due to its close resemblance in color to citrine, yellow to orange "actual topaz" were termed "precious topaz" to distinguish between them. Topaz comes in many hues, from colorless to yellow, blue, brown, red and everything in between. The colorless and pale blue stones are most abundant in nature, followed by yellow and brown stones, while the golden-orange, pinks and reds are most rare. The latter are mostly mined in Brazil.
Because of the softness of pure (24k), it is usually alloyed with base metals for use in jewelry, altering its hardness and ductility, melting point, color and other properties. Alloys with lower carat rating, typically 22k, 18k, 14k or 9k, contain higher percentages of copper or other base metals or silver or palladium in the alloy. Copper is the most commonly used base metal, yielding a redder color.