Quick Answer
Quinoa (dry) does not use the same grams-to-cups value as every other ingredient. Using a practical US cup reference, 170 grams of quinoa (dry) is about 1 cup.
That means 100 grams of quinoa (dry) is about 0.59 cups, while 200 grams is about 1.18 cups.
Dry quinoa is a small grain that settles moderately in a cup. One US cup of dry quinoa weighs about 170 grams.