I don't understand what you are asking.
Anyone can create a website to sell diamonds, but you'd actually have to deliver for it to work right.
If you are in that type of field (i.e. jewler etc.) and you can supply cut and design diamonds what's illegal about owning a site that can do it online.
Now from a shoppers pt of view they may have mean questions about the diamond, and rather it was a blood diamond etc. That is probably why many don't shop online for diamonds but rather in stores.
To answer your question simply. If all the legal stuff is straightened out (i.e. diamonds are stolen or blood diamonds) then I don't see anything illegal.
I saw a thing on TV talking about the whole "blood diamond" issue and they basically said that during the 80-90s (maybe even more recently), the world's largest supplier of diamonds knew about the issue, yet still continued to profit off of them. And they were the supplier for pretty much any store that sold diamonds. I honestly am not aware of the situation today, so I'm sure things have changed, but all I'm saying is that even if you go to a respectable store to purchase something, anything, you never know what someone had to go through in order for it to get there.
And to the OP.. There is a company named Diamond Stardust Corp. who sells diamonds, so unless it's a generic term pertaining to jewelry, which it doesn't seem to be (only 1,300 Google results for "diamond stardust"), I'd say you probably don't want to use it...
I was actually worried about this because the term "Stardust" seems to be trademarked.
So my question is whether it is legitimate to use this term in any context, like in this case with the word Diamond?.
Yep, there is a company named Diamond Stardust Corp., though they haven't trademarked their name.
Not sure if this company is still alive...
They don't have to TM the name, there is such a thing as common law TM. They pretty much just need to prove that they've been using the name in commerce before you. As for whether the company is still alive or not, I have no idea, didn't research it that far..
Ahh.it all makes sense now.
If that was in the first post I would have gotten it.
As slipxaway mentioned as long as they did commerece first with that name then that's really all the proof the need.
I wouldn't grab this name if it was me.
Thank you guys for your valuable info. What I need to do now is to find out if the company existed before I registered the name..
To slightly correct your phrasing, it should read "you don't have to have a registered mark to the name". Using it in commerce gives you common law TM which in itself a TM to the name. (or at least an arguement to have a common law TM)..