Antique Victorian Pendant Locket Gold light yellow Diamonds Enamel Cross (7462)

Antique Victorian locket pendant. Gold, enamel, pale yellow diamonds, glass. Made circa 1850 - 1880. See below for origin.  

Measurements: Weight is 8.9 grams. Length including the bale is 1 1/2 inches (4.8cm).  Length excluding the bale is a little over 1 inch (3cm). Diamonds approximately 1.50ct. Note: antique diamonds do  not conform to modern formulae, so the measurement is approximate and should be seen as a guide or suggestion of magnitude. 

Description : An oval shape with scalloped edges. The gold surface very richly engraved with scrolls that conform to the undulating edges and then form concentric scrolls within. This forms an outer border. Within, is beautiful rich, royal blue enamel enclosing a raised cruciform set with fabulous old diamonds. The arms of the cross are oval diamonds and the center is a roughly square old mine cut diamond.  The cut of these diamonds indicates that they are extremely old. They are simply faceted and so high as to be almost round.   Diamonds are a well-matched pale yellow color. 
The back of the locket pendant is also very richly engraved gold. An interlocking Gothic or Celtic pattern, with foliage and scrolls adding further detail. 
The bale of the locket, connected by a small gold loop is of foliate form and is enamelled in the same rich blue as the area surrounding the diamonds.
A hinge on one side holds the two parts of the locket together. It opens to reveal an oval reserve, covered in what appears to be very old glass for protecting the loved one's portrait or lock of hair. The richness of the gold is very clear on this almost pristine inner section of the pendant. 
Beautifully made. Very rich and luxurious. Luscious old diamonds.  

Marks and Metal: Gold was tested as at least 18k. 
Inside the locket is hand-engraved 1797 with what appears to be a much later 4667. It is unclear what these numbers mean. 1797 could be a date, but the style of the pendant is more Victorian, so we will leave it to the buyer to decide.
The loop and bale have the remnants of hallmarks, quite illegible today, but one looks like the remnant of a French maker's mark lozenge. 

Condition: Good with minor wear commensurate with age.  Please see enlarged pictures and don't hesitate to ask questions which we will do our best to answer.   

ORIGIN: The collector who sold me this jewel believed that it was French. In the absence of clear hallmarks, I am reluctant to claim this origin. The country of origin will remain a mystery for now. It does not detract from the beauty of the piece. 
What makes this pendant a standout is the quality, shape and color of the diamonds. They are clearly very old and of a light yellow color that gleams beautifully against the very bright, high karat gold. In addition, it is unusual in old jewelry to find such well-matched stones.    

Note: The chain shown in some of the pictures in not included with this pendant.