These Skeksis eating utensils were acquired from the estate of Harry Lange, the production designer for The Dark Crystal. Lange, who died in 2008, worked with Stanley Kubrick on 2001 as well as Jim Henson on The Dark Crystal and The Great Muppet Caper. I closely inspected every shot in the film where these props were used and unfortunately was unable to match them anywhere so I hesitate to classify them as "screen used". But I did anyway.
Upon researching these props I read that Mr. Lange made 10 sets for the film even though the scene they appeared in only had eight Skeksis, 21 fingers (one Skeksis only had one hand!) so thats 30 utensils and only eight utensils in all appear in the banquet scene.
This is gonna get super geeky... From the far left: "The Gourmand" had no utensils, next, "The Scroll Keeper" has none on his right hand and one on his left, couldn't tell what it was though. (1) "The Ornamentalist. right hand: BLUE jeweled fork, GOLD jeweled knife. Left hand: BLUE jeweled fork and a spoon (couldn't see color) (4). next, "The Ritual Master" Right hand: none, left: PURPLE jeweled knife. (1) "The Garthim Master, None on either hand, "The Scientist" Left: none, Right: BLUE (something, maybe fork, could be a knife) (1) "The Treasurer" Left: none, right: PURPLE jeweled, looked like a fork. (1) And last, "The Slave Master" No utensils, just a big hook where his left hand would be.
This is what I was able to see.
In the book "The Making of The Dark Crystal", on page 45, "The Gourmand" or Gourmet as he is listed, has a full set on his right hand, all BLUE jeweled and silver.
The utensils in my set have a GOLD jeweled fork, RED jeweled knife and BLUE jeweled spoon. I saw no combination of utensil and color of any of them in any shot but the jewels could have been replaced once or twice over the past 32 years. They are also tarnished so that they appear more on the gold/brass side opposed to the original silver/pewter.