Hi, I have 40 years experience cutting precious and semi-precious stone and may be able to help a bit. Most of your bead is "country rock" while a small potion , the brightly colored area, is jasper, a type of opaque quartz.On the left of the bead in the first image you have what looks to be a vug, a small gas cavity that is now filled with what looks like small quartz crystals , quite standard. No agate at all. Agate is translucent to a degree and is often banded as it is deposited in layers by fluids , usually ground water saturated with silica leached from the host rock.

Here is a typical Idar-Oberstein stone bead, presumably made of agate per Frank's description. One side has a nice banded figure.

I have seen the more opaque jasper faceted rounds such as shown in the IP, but I don't have any in my collection at the moment. However nearly all the Idar-Oberstein beads I've seen were clearly the more translucent agate stone.

Another comment - many people confuse the almost identical-looking, dark red-brown glass faceted round beads from Bohemia with the stone beads from I-O and they are sometimes found together on the same strands.

Although stone beads are not my strong point I believe this could be an agate Idar-Oberstein bead. I thought it would be good to compare the differences between the bead in question.

Matt

Idar beads are largely from two different geological sources, Idar area itself and the vast agate fields of Brazil. Most of the beads we associate with Idar and the African trade are agates from Brazil, the vast majority of which are treated by either soaking them in sugar then heating them in acid or just dying them with various aniline dyes.Most Brazilian agates are rather insipid in color and contrast but they are very large, wildly abundant and take dyes well so they make a perfect industrial media.Very little attention has been given to alternate sources of agate and jasper for the Idar mills but I suspect that as the Idar supply diminished there may have been imports from northern Africa. Many localities have limited amounts of agate similar to the agate used in this bead. The color and " sleepiness" come from fine hematite that is evenly
dispersed.

At first glance, this bead does not look like a 'typical Idar-Oberstein agate bead'.
That is because the typical beads that we see as Idar-Oberstein beads are those that were made from (mostly) Brazilian agate that was used to make beads in Idar-Oberstein since the 1830's.

Before they started using these types of stones, the Idar-Oberstein region already had a history of cutting agates and other locally found stones. These stones were generally of a different type than the Brazilian ones with quite a different appearance. The first record of agate cutting in Idar-Oberstein goes back as far as 1454.

So it is possible that this is an 'older generation' stone bead, cut and sourced from Idar-Oberstein. This would fit with the timeline that is suggested. I have not seen examples of any older beads (before the Brazilian agate) in the Idar-Oberstein museums, so that makes it difficult to really know anything about beads from that time period for sure.

I am no stone expert, but I would agree with Frank that it looks more like jasper than agate.