This order is for approximately 1/4 ounce of copper carbonate powder. It's used in fused glass to create a light blue bubble texture when fused between layers of glass. This produces many tiny tiny bubbles in the glass, as opposed to Copper Oxide, which produces larger bubbles. However, it takes about twice as much powder to produce a uniform layer of bubbles. Copper carbonate is much lighter than Copper oxide, and as a result, the bag will appear as full, or fuller, than a 1/2 ounce of oxide powder, despite being only 1/4 ounce. The amounts are in 1/4 ounces to be able to offer free shipping through postal mail. This is an excellent sample size to purchase before choosing to purchase a quarter pound or more from a ceramic supply store. The sample in the image were made with the same copper carbonate as you will receive.