I'm pretty sure you mean Sapphire Diamond which reduces the colorless cost of your Blue spells by 1. You're only allowed 1 Mox Sapphire (which does what you describe).
By the way, decks like those were one of the reasons why I quit M:tG.
No, definitely not the medallions from tempest (which were too ex for me) nor the mox (come on, in a $10 deck?). Mirage had these artifacts which cost 2 colourless mana each, and came into play tapped. You could tap it to add one mana of the appropriate colour to your mana pool. I only recall the white version being called marble diamond.
I wouldn't rate my deck as being particularly strong (though it is fairly effective for the amount of money I spent on it). I found that it had problems with lightning fast decks like sligh and suicide black, since I can't do anything on the 1st round and tend to be defenseless on my 3rd round (when the temptation to tap out for an ophidian is very strong). Quicksand screws with you mana-wise, while allure is too slow vs weenies.
But if you could survive until the 5th or 6th round, things will generally get easier. And victory is more or less assured if you can get up to 12 mana (unless you are facing another counter heavy deck). Later on, you win by spamming capsize (lockdown is inevitable when you can capsize 2 land/round), while holding a fistful of counterspells (remember that forbid is a reusable counterspell) and beating down with a blue flier.
I have tried other playing styles, but finally decided that permission decks were the most enjoyable and fulfilling to play for me. Weenie/burn decks got boring quickly while combo/gimmick decks were too unpredictable (not that they were weak though).
Other control decks I have tinkered with included propaganda-winter orb (but felt a little too metagamish, considering that a fair number of my friends liked to play with creature decks, and this deck made me feel like I was specifically exploiting their weakness, making victory feel less satisfying), 5-colour blue (too expensive overall, I had to proxy heavily, and a little overrated in my experience for all the hype surrounding it), marrogeddon, turbo-xerox (cycling through your library with 17 cantrips was fun, but overall not all that strong) and counter-burn (very slow, even moreso than a conventional blue deck).
What are all your favourite deck archetypes?