Posted this before, here it goes again:
Ironsilk is the only tier V resource with neither plots nearby nor machines to make spools:
Tier V Gems -
Periodot/Emerald- Gem Shop short run away
Fire Opals - machines in near by cave
Yew - woodshop in the field and nearby plots in Mith's Anvil
Mithril - plots surround the entire area where it spawns
Marble - plots south of marble spawn
Wisps - Yew wisps have access to Mith Anvil plots. Spiritous Swamp Wisps have no love tho.
Edit:
Ironsilk is also the only tier V resource that does not have multiple spawn points.
Gems - Ice Island/Fire Island/Saritova Island
Mithril - Near Mith's Anvil / Saritova Island
Marble - Near Mith's Anvil / Saritova Island
Yew - Near Mith's Anvil / Saritova Island
Wisps - In Yew Spawn / Spiritous Swamp
Earthen Craft - with marble in both places I believe.