The approx. knot count is 4H x 6.5V per sq. cm.
There is an unusual feature in the design of this rug, the inverted crescent at the top of the central panel. This is very similar to the inverted crescent seen at the top of the panel of a millefleurs prayer rug attributed to 18th century Persia [very possibly from Fereghan] that is in the Victoria and Albert Museum (Layla S. Diba, "Carpets X, Afsharid and Zand Periods", Encyclopaedia Iranica, vol.IV, p.876, pl.CXIII). In that rug it could well be a moon contrasting with the blazing sun floral spray immediately below. If one were to continue the analogy then this would be the moon with the myriad stars in the night sky that here are represented by flowerheads.