Math Vocabulary

As I was reading through the information on VanHiele levels, specifically where it mentions vocabulary, a thought popped into my head. I told one of my colleagues (who is also a good friend) to stop using the word diamond when referring to the blue rhombus that is part of a standard set of pattern blocks. (She is a 2nd grade teacher.) I told her if she wasn't going to use rhombus, then she should at least use parallelogram. She disagreed with me at first, saying that 2nd graders don't know the word parallelogram, but I told her that if she taught it to them, they would! I would not expect her 2nd graders to list properties and characteristics of parallelograms, but shouldn't they at least be exposed to the correct terminology? BTW, this teacher did start to use the term parallelogram and commented to me later that most of her students recognize what she is talking about when she uses the term. :)