In the context of measurements for cannabis or other substances, a "quarter" typically refers to one-quarter of an ounce.
Since there are 28.3495 grams in an ounce, a quarter (or one-quarter of an ounce) would be:
1/4 * 28.3495 grams = 7.087375 grams
So, a quarter is approximately 7.087 grams.