Got arrested with 1.7 grams of marajana on school property. I will turn 18 in 5 months. Is this enough to charge me with because the cop called it an unusable amount?

A.R.S. § 13-3405 is a law in Arizona that makes it a crime to knowingly possess marijuana for sale or to knowingly possess, use, or produce marijuana. Also, that statute explains the violations depending on the weightof marijuana. For example, a person who knowingly possesses or uses marijuana (not for sale) is guilty of a class 6 felony if the weight of the marijuana is less than 2 pounds. If the weight is at least 2 pounds, but less than 4 pounds, it is a class 5 felony. If the weight is 4 pounds or more than it is a class 4 felony. (A.R.S. § 13-3405(B)(1)-(B)(3)).

When dealing with marijuana, a usable amount may be very small.  In a number of cases it is less than 1.7 grams, and can be a small portion of a leaf.  Generally if it can be burned and potentially smoked or ingested somehow, it may be a usable amount.