So I had to get nosy and do some research because It's never occurred to me that this kind of effect was possible in the 19th century (upon reading the origins I was like "Oh Shit That's what that is??").
Fabric is made up of basically two parts while being woven, weft (which goes side to side), and warp (which goes up and down).
This dress is made of Shot Silk, so named because of how the weft bobbin of a different color is "shot through" the warp color while the fabric is being woven. The silk in the original post is probably "Dove silk", made of turquoise and magenta fibers which makes that striking iridescent grey color. It was popular all throughout the 18th century, especially in French fashions, and gained a popularity during the American Civil War (cotton production was disrupted and yielding smaller crops as the enslaved peoples involved with production of cotton were dealing with bigger fish to fry, like seeking freedom from slavery and trying not to die).
You might be more familiar with its use in cosplay spaces, specifically with One Disney Princess In Particular
This fabric has so much potential in modern garment making, and I'm so shocked no one else has latched onto it for period pieces. Especially when we have documents suggesting that this technique has existed in Noble and Clergy circles since THE 700'S
Shot silk! What a concept!
yes! shot silk/changeable silk is so pretty. I see it fairly often in late 50s/early 60s party dresses, usually in really intense green/blue but sometimes in pink/orange or blue/purple.
This is what my university uses for the stoles of graduation gowns. Arts get blue-green, engineering gets red-orange, and science gets yellow-vomit