"Iris Glass" or "Rhinestones"
The use of natural
rhinestones (Cailloux du Rhin) is recorded in Germany and Frances since
at least the 17th Century. This variety of quartz is also called either
rainbow quartz or iriz quartz because of the amount of iridescence it
shows due to its internal fracturing. Itis found in the Alps and is
brought down to the valleys by such rivers as the Rhine - hence the
The Bohemian makers of the Gablonz area introduced a new type of artifical
gemstone that excelled with an outstanding sparkle. On small stones
it was hard to tell why they had such fine sheens, only the larger stones
revealed that it was achieves by simply including (generally three)
transparent filaments of green, red and blue into the otherwise colorless
glass. As the natural rhinestones were most frequently rainbow quartz
(iris quartz), i.e. a type of quartz that displays a certain iridescence
because of internal fractures, the makers call this glass "iris
glass," while users stick to the term rhinestones.
Many jewelry pieces were made with these "rhinestones" from
Gablonz and Germany, after World War I. The "rhinestones"
of the late 19th century (pre World War I) have much stronger colors
than the more recently crafted stones.