Featured Red-Stoned Brooch

Beautiful brooch. I love this style.

The other term is 'Algerian knot'.
It was introduced in mainland Europe when the French conquered Algeria in 1830, which started another Orientalist craze (you know me and Orientalist).
By 1840 no self-respecting woman of some means could be without the Algerian knot, whether in jewellery, clothing, accesories or home decor. Preferably all, of course.

Algerian knot jewellery started in Continental Europe in the 1830s and continued until the 1860s, so I would date this beauty at least 1860s, which also accounts for the long pin. I don't see evidence that the pin is a replacement, but it is early morning here.
Victorian Britain and North America may have caught the Algerian bug a bit later than Continental Europe, but, from what I've gathered from DB's family history, this could well be a Continental piece. So I am comfortable with it being at least 1860s, during that time garnets were already popular, just like later on.

It looks like the garnet spray is silver, which is not unusual, because it was thought silver reflected light better than gold. Precious stones were often set in silver, the rest of the jewel would be gold(plated).

The garnets are Bohemian, as Obb said, mined in the region of Turnov, just north of Prague. Turnov is not far from Jablonec, but was a garnet centre long before.
The stones were probably cut in Turnov as well. Rose cut as rufus said.
From ca 1600 the Austro-Hungarian court took a special interest in steadily increasing mining in Turnov, to combat poverty in the region. Turnov was not only the main garnet source of Europe, but became the main garnet cutting centre of the Western world in the 18th and 19th century.

As rufus noted, it looks like the bigger garnet is chipped, and the dark spots on the back could be wear. In which case the brooch would be gold plated. Gold plated still has value, because of the age and the popular design.

If your niece is not careful with jewellery, it may be wise to wait until she is? None of my business, I know. (just love jewellery)

 

I meant the use of what are like segments of tubing to create the shape, not the shape they are arranged in. This is an example of the sort of thing I see a lot. The plain tubes on this one that are open on the front weave around & have a closed end that comes out on the back. The decorated bits show the closed end while the other has been crimped down flat & does not go through to the back. As you can see, it is not gold. Best word I can come up with for settings like this is 'tubular'.

 

I'm sure tubular is a good term for the component that makes up the knot.
That brooch(?) would also be considered an Algerian knot. Any shape made of intertwined tubes is called an Algerian knot. The tubes are a good way to achieve the intricate shape, although the knot can be made with other bold intertwining shapes.
Here is a modern take on the knot, also called Algerian by the desgner:

 

Wowwww, That cameo looks like an antique
Congratulations for your superb buy!

 

Thank you once again. The cameo itself I think is Georgian. Only the pearls around it may be from the original setting. The garnet extravaganza was added later. Will post it when I get it & show how it is put together, very unusual.

 

It is beautiful, do you know who it represents yet?

Extravaganza indeed. The Victorians loved to go ott with just about everything. Beautifully executed, though.

 

Interesting, also called love knots or Algerian love knots. Wondering whether the inspiration would have been something like stems, reeds or grasses twisted & intertwined? Even one in carved jet preserves the 'tubular' pretzel with blunt ends look & settings like mine look a lot like grapevine wreaths.

It's a brooch. The scene is of maid servants preparing the bridal chamber & the bride for the wedding night, so a love knot, Algerian or not, is appropriate.

 

Thank you too, AJ. None of seller's pix was in focus & taken straight on, so I'm not clear on some of the details. I'm better with mythological figures than with the historical ones. For the moment he has to be one of those unidentified classical philosopher/poet figures. I take comfort in knowing this is the best museums can do in many cases.