It is a silk thread, but Kreinik no longer makes it. I did find an old conversion list for this to DMC, and it is similar to DMC 729, a gold color. The site said that the Silk Mori and Silk Serica lines have replaced the old Sioe d'Alger. But I couldn't find the Silk Mori equivalent to 729.
Wendy Jones

Current Rotation:: Knotwork Winter (Dracolair), Renaissance Angel stocking (Vermillion), Santa's Magic (Mirabilia), Queen Anne's Lace (Lavender & Lace).

2006 Completions: Celtic Winter (L&L), Easter Fairy (Mirabilia), My Lady's Garden (Mirabilia)