Martin uses bone on its guitars; Gibson and Taylor use a synthetic (Tusq) that they insist is better tuned to conduct the frequencies particular to guitars. Gibson also uses Micarta and Corian. Most of us would likely never really hear the difference. I bet these materials are harder than at least most woods, and likely conduct better. However, I suggest that, like all other musical instruments, it’s not really a concern of the material of one component, but the synthesis of all build factors. A bone nut will still sound bad if the total build is suspect. 

I prefer hard woods for nuts and bridges -- the harder the better -- Lignum vitae, Snakewood, Ebony for exotics, Madrone, Osage Orange, Blue Beech, for American hardwoods.

The only place I've used delrin is as John noted; bridge caps on the hammered dulcimers I've made. For mountain dulcimers I've used ebony, rosewood, walnut, oak ,and micarta. Each provides a pleasant sound. As to McSpadden using micarta, that would be for the bridge/saddle as they don't really have a nut since they use a zero fret. Now as to whether these materials are better than bone, it is subjective. Bone tends to give a sharp, crisp sound as does ebony. The other woods tend mellow out the sound depending upon hardness; at least to my ears.

Ken

"The dulcimer sings a sweet song."

In my opinion, any stiff and dense material transmits the energy well. Metal, plastic, bone, dense hardwoods, etc. Each will slightly alter the tone of the instrument, but only very slightly. I often use hardwoods out of convenience, or a metal zero fret for consistency of tone, but bone is my preference because it transmits super well, and I like the look of bone best. I'm not a big fan of the premade plastic ones because they are harder to alter, but they sound just as good.

updated by @nate: 08/03/24 11:33:24PM

Welcome, Jon, to our little world!  We're glad you're here.

As to your question of the differences between bone and Micarta or Delrin, all I can say is that I've used bone and Micarta, but not Delrin.  All sounded fine to me.  Bone is a bit disagreeable to cut (gives off the same smell as a dentist drilling your teeth), but has excellent sound conduction because it's so dense.  It's also very traditional for use on dulcimers of the past.  McSpadden makes extensive use of Micarta, and they claim it's superior to bone.  I think it's fine for nuts and bridges. Delrin is known for its lubricity, and is sometimes used for HAMMERED dulcimer bridge caps.  Seems strings would be less likely to hang-up when tuning.  I haven't yet encountered it as a dulcimer nut material. 

Hi kids hoping to pick everybody's brain. has to do with nut and saddle Material 

I know folk craft uses (plastic) nuts and bridges, Micarta, Delrin.  My question has to do with the material, are These materials better than bone? or is bone a much better material ? Okay that's it kids thanks again for all the good information.  So what do you think