artificial turf
It is astroturf. The field was replaced with field turf in 1999 with Ditka's ok and then replaced with an improved type of astroturf after katrina.
The emblem is for the Gillette Stadium. The emblem stands for a bridge to the stadium and a 12 story lighthouse at one of the entrances. The Yellow coming from the emblem is the light from the lighthouse. Please refer to the related link for an image and more information.
No. They play on the same natural turf.
The artificial turf that was installed recently is called AstroTurf GameDay Grass 3D. There is a lot of controversy around the decision, apparently there are some people who don't like the idea. However, as of September 2012, the new turf was being installed.
The San Diego Charger's home field, Qualcomm Stadium, is a grass field.
Turf
The Cleveland Browns Stadium uses grass, not synthetic turf. "The field is a Kentucky Bluegrass irrigated field with a sand-soil root zone and an underground heating system containing nine boilers and 40 miles of underground piping. The heating system helps to keep the field from freezing and extends the growing season of the turf. Field has been designed to accommodate international soccer as well, with dimensions of 69 yards by 114 yards."
probably turf or grass
That is correct. Both the Giants and the Jets both share the same field. If you are wondering how the endzones change colors, the turf is removed, new turf is put down and the turf is spray-painted.
The New England Patriots installed a new playing surface, field turf replacing the natural grass, in November of 2006.
Turf hockey is field hockey.