Mostly some synthetic as it has a sheen and the silky feel.
Which betrays being 100% cotton. The sales information from
the store where it was sold and (I bought it at an estate)
said 100% cotton. But it is very nice fabric, medium weight.
The picture was scanned and it didn't show up as dark as
it really is. It is a dark turquoise and is very rich in color.
You can see the selvage edge in both pictures, which tells
us it is not cotton. I burned a tiny piece of the fabric; it melted.
If you need more, I have the same piece in the quantity of 5 1/2 yards.
It is a piece I purchased from the same estate sale.
Just check my ebay store for that and other fabrics.