Here is a nice and inexpensive Tektite from China. I do have more of these in this same price range as I was able to but a large quantity of them. Let me know if you want additional pieces. The picture is of the specimen you will receive.

Size: 1.25 x 1.05 x 1 inches

Tektites are most likely derived by large hypervelocity meteorite collisions with the crust of the earth. They are often rounded, pitted bodies of silicate glass. While commonly about the size of a walnut, tektites can vary from the size of a sand grain up to large, blocky, Muong Nong-type specimens weighing up to (28 pounds). Tektites can differ in both color and age, depending on where they are found. Commonly black color, tektites can also vary from light green to greenish yellow.