Antique Art Nouveau late Victorian necklace that converts to two bracelets. 18k bi-color yellow and pink/red gold. Made by Edouard Aim  Arnould in Paris, France, circa 1895-1905.  
Measurements:
Weight is 45.5 grams. Total length not including the tongue: 16 1/4 inches (41cm). Length of bracelets: 9 1/4 inches (24cm) and 6 3/4 inches (17.5cm). 
Description :
Heavy, solid chased 18k gold. Oval openwork chain links with fully relief modelled chased foliage and flowers. The flowers are in red/pink gold while the rest is in yellow gold. Beautiful detail - leaves look to be geranium or similar with every vein shown. One shown viewed from the front and one from the back. Stems twine around one another. In the center is a beautiful flower - again with the same exquisite detail and modelling. 
There are a total of 14 stations, including the divided stations that form the clasps. 
Smaller, oval gold links connect these stations, allowing for flexibility to wind chain around neck or arm.
There are two clasps, allowing the necklace to convert to two bracelets - of differing lengths (see measurements above). 
Tongue in Groove clasps click in securely and have additional safety catch to each of them. Clasps identical to the rest of the sections, invisible besides the safety clasps when closed. 
Marks and Metal:
French eagle head marks on the tongues are very clear (for 18k gold, made in Paris). Another mark, next to the eagle heads, not clearly legible is probably the rhinoceros head, used to mark chain link items. 
Side of one of the links (5th from one side) is engraved ARNOULD for Edouard Aim  Arnould.     
Condition:
Good with negligible wear commensurate with age.  Please see enlarged pictures and don't hesitate to ask questions which we will do our best to answer.   
THE STORY:
Edouard Aim  Arnould was a jeweler best known for his Art Nouveau designs and his collaborations with other artists notably the renowned Alphonse Mucha, Toulouse-Lautrec, and Manolo Hugu . He also manufactured jewelry for other jewelry retailers.  His customers included European royalty and prominent cultural figures and he won a gold medal at the 1900 Exposition Universelle in Paris.  One of the traits of Arnould was his discreet signature. It took me a long time to find the mark on the side of one of the links and the person who sold me the necklace/bracelets was not even aware that it existed.