Antique snake necklace heart locket gold GIA Burmese sapphires provenance (7550)

Antique early Victorian snake necklace and heart locket. 15ct gold, pink Burmese sapphires (Myanmar) w 2 GIA certificates and extra independent gemological appraisal. Made in Great Britain, no later than 1853 (dated). 
Great provenance: given by the famous British (Scottish) chemist Thomas Graham to his sister, Mary Reid. 
 

Measurements:

Weight is 35.9 grams. Total length is approximately 16 1/4 inches (41cm) including the locket. 2.46ct pink sapphires. 

Description :

A truly exceptional snake necklace. The body is composed of articulated bright gold links that emulate the slinky, slithering body of the snake, tapering and broadening in a naturalistic way. The neck and head are superbly adorned with deeply chiselled and textured gold work, arching raised feathery gold brows, colette set cabochon garnet eyes and the most intense bright, hot pink sapphires that are sure to draw every eye in the room. Like many of the snake necklaces from this period, it also has a heart hanging from its tongue, but in this case, again, the heart is so much more than the norm, with the same intensely chiselled gold work in foliate patterns and set with the same vibrant pink sapphire. The back of the heart is a locket that currently contains the picture portrait of a previous owner. She can be removed and have your own portrait or lock of hair inserted. 
Tongue in groove clasp. As is the norm for snake necklaces of this type, the clasp locks in front - into the side of the snake's neck.  This makes it very much easier for a lady getting dressed (instead of fiddling around at the back of her head). 
The snake was very definitely made in Great Britain, but it was sold in France, as evidenced by the shell mark (see below). 
Superb workmanship, design and materials. Versatile - can be worn by anyone, for any occasion.
Provenance: from Thomas Graham to his sister, Mary Reid. See 'the story' below. 

Marks and Metal:

Tongue of clasp is marked 15CT and has French shell mark (which denotes 14k in France. the French did not use 15k). Behind the head, the 15 CT mark and engraved: FROM THOMAS GRAHAM TO HIS SISTER  MARY REID AUG 1853. 
Interestingly, the gold was electronically tested twice by our appraiser as at least 19k. This is a classic example of the heterogeneity of antique gold - it was not made with computer accuracy and often varies from place to place, depending on where it is being tested. We will of course guarrantee at least 15k. 
Because we were so curious about the discrepancy between the appraisal and the engraved mark, we took the necklace to a metallurgist with really high end equipment for testing metals. The appraiser was correct: despite the mark of 15ct, the gold tests well above and ranges from over 18k to 19.9k. 
     

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: 

 Thomas Graham FRS FRSE DCL was a Scottish chemist known for his pioneering work in dialysis and the diffusion of gases. He is regarded as one of the founders of colloid chemistry. He is considered a great pioneer in chemistry and science. A quick look on the internet tells us that he was the 2nd of 7 children. Why did he give Mary, the 5th sibling, this necklace? Were they especially close? Was there a special occasion? We know that gift-giving was an integral part of life in previous centuries, but it seems that a fabulous and unusual necklace like this might be for a special occasion. It's amazing to know about the original owners of this necklace - exactly who they were, where they lived and the huge contribution they made to our own world and body of scientific knowledge. 
Snake jewelry has been very popular since ancient times. Snakes feature in jewelry of the Ancient Egyptians, especially the Ancient Greeks and Romans and then again from the Renaissance onwards. It is highly symbolic, not least indicating eternal life and love. The snake trend got a huge boost when Prince Albert gave Queen Victoria a snake engagement ring. At about that time, this kind of necklace, with inset gems and adornment of every variety became almost a cult, with both the English and the French aristocracy and richer members of society (who could afford them). Usually, when we see snake jewelry from this period, we are looking at a superior jewel. This necklace is even better than most. The bright pink gems and detailed botanical work are exceptional. This necklace, in my opinion, is a real 'wow'.