What Patten was grandma using

[soggycashew]

Hello, I want to crochet a blanket the exact same as what my grandmother did for me for my daughter and I can't figure out what pattern is used. My sister said she remembers her saying something about double stitch when she made them years ago. The blanket is very very heavy and not light at all, any ideas? Thanks! 

[Granny Square]

It looks like a stitch that has a couple of names, crazy stitch, brick stitch, and probably more that aren't coming to me right now.  It's the same stitch that those corner-to-corner picture blankets use.  There are variations that use a different number of stitches, but usually 3 or 4 in each shell.  It looks like it was done tightly.  It might be made of cotton?  That would make it heavy, and the way the stitches appear after some wear looks like a possibility.

https://www.thespruce.com/how-to-crazy-stitch-in-crochet-4061423