Strangely Thick GE 40W F15 Incandescent Bulb

Here is a GE F15 soft white incandescent light bulb. It has extremely thick glass for some reason. You can see how far the outer edge is from the internal silica coating. Very odd quirk, but it makes for a neat-looking bulb. Other than that, it's nothing out of the ordinary for F15 bulbs. It features the fire effect molded into the glass. It is 40 watts and 120 volts. It has a medium base. Nothing all that special, just extremely thick glass.