Part of the ‘Antique Fabrics’ series, this fabric isn’t necessarily extinct, but it was more popular in the past than the present.
I’ve run across this one in several 19th-century catalog reproductions so, clearly, it used to be popular.
Today, silk crepeline is used in textile preservation. I haven’t encountered any variety for modern garment use. For a good-enough substitute, I’d suggest a lightweight crepe.