Druidic Breastplate (3.5e Equipment)
From D&D Wiki
A Druidic Breastplate is a special variety of breastplate invented by druids some 100 years ago. It is made of ironwood, worn over a suit of Leatherweave leather armor. It is functionally identical to a masterwork breastplate, aside from different composition and appearance. The approximate value for such a suit (non that most druids would know) is 500 gold pieces.
A rare variant uses mithralwood instead of conventional ironwood (see the Greater Ironwood spell description), and is functionally identical to a mithral breastplate (light armor, arcane spell fail of 15%, maximum dexterity of +5) with an effective value of 4500 gold pieces (again, most druids don't know this, as most of them don't deal in money).
As druids are the only ones capable of crafting such a suit, it is all but unheard of for a non-druid to own one. Chaotic, True Neutral, and Evil druids do not look too highly on non-druids who wear one (and may attack on sight), while Lawful and Good aligned druids will be very annoyed and demand that the non-druid remove it and return it to its "rightful" owners (the druid order) before potentially becoming hostile.