An odd set of specifications.

Is the melting point the only temperature you're bothered about? Lots of metals experience significant property changes well below their melting points.

Do you want to be more specific about the conditions you want it not to corrode in? (To some folk, 316 is corrosion-resistant: In my world, it rots faster than you can replace it)

Mohs is a really unusual scale to use for metallic hardness (and no strength requirement?).

How cheap is fairly cheap? Are we talking cheaper than gold, cheaper than Inconel, cheaper than Stainless?

kovar has 1449C melting point

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

For aesthetic and artistic purposes, I'm trying to mix clay with small bits of metal and then cook it at ~1200.c, and then wet sand it to reveal the lustrous metal aggregate.

I have successfully done this with stainless steel, titanium (below) and molybdenum. It looks great. But I want to find a golden colored alloy also. Copper unfortunately melted and oxidized of course.

(Other colors like blue and red lustrous alloys would also be cool)

If it’s cheaper than gold it would be good.
The corrosion resistance and hardness isn’t so important. I just don’t want it to oxidize in the kiln or after it’s cooked.

Monel and other copper/nickel alloys might work. If stainless didn't oxidize so badly that you couldn't sand back the scale to bright metal, then monels might work too, esp. if they have a small amount of Al in them. Aluminum-Nickel bronzes might also work.

The combination of Yellow/Brown and high melting point is a tricky one. Closest I can see is Nickel Ally Bronze - but even that falls a bit short of your 1100C.

The Monels I've worked with tend to be white.

IRstuff's suggestion of Kovar sounds inspired (if not cheap).

A.

I may have the name wrong, cupronickel alloys high in copper can be a golden yellow.

@btrueblood, Monels are generally Ni>Cu. When it's the other way round, it's cupro-nickel. For what it's worth, we use a lot of 70/30 CuNi in high pressure pipework - and even that is white. On the other hand, 90/10 is quite coppery in appearance and actually just scrapes in on the melting point front, so that could be a serious option to look at.

A.

Thank you for the cupronickel suggestions. I'm going to order some CuNi brake line fittings and cut them up.

I also came across Molybdenum Gold cutting wire (aka EDM wire).

I will also try Hematite.