This is a small, tipless carbon filament bulb, with a deep Ruby Red envelope. It is quite heavy for its size, with a very thick glass envelope. This bulb may have been meant for use in a darkroom lamp, for developing black & white film. The filament in the picture of it lit appears to show a purplish/pink color, but in reality it gives off a deep red hue. Here's a picture with much more accurate color. I am not entirely sure if this bulb is an antique or a vintage bulb, given that it is a tipless bulb you might be tempted to say that it is vintage, but I suspect that this bulb may be an early attempt at creating a tipless bulb, because the lead-in wires seem to be made of platinum (as far as I can see, the glass is so thick and deeply colored that it's real hard to see the inside, even against the sun), and because I do not see an exhaust port inside the stem. But without a clear view of the inside it is very difficult to tell if it really is a genuine "early tipless" bulb (made in 1906-1910), though going by how thick the glass is, it might be. For now though, it will remain in the vintage gallery, since it is well known that tipless bulbs went mainstream in 1922.