So much for the impact of the resources rent tax — whatever it is called —  on the Australian stock market.

The excitable among the commentariat defied logic and claimed it was one of the reasons why the Australian share market was falling in April, May and June, despite evidence to the contrary that markets overseas were falling and the prices of key commodities such as copper were also dropping like a stone.

So when the tax was reworked, leaked overnight and then announced at 7.50am (when the release went out), there was considerable expectation that the market would ignore another bad night on Wall Street and open higher, which it did, for about 90 minutes.

The damage to the prices of mining stocks has been done by the 17%-plus fall in copper prices, 23%-plus drop in nickel, double-digit falls for other metals and a 12% drop in oil prices, with gold slumping $US46 overnight to finish about $US1200 an ounce.

The market closed at 4263 Thursday for the All Ords, opened a whole 11 points higher this morning, peaked at 4303, fell to 4270 and then recovered slightly to be up about 14 points by 11.45 am. Yes, the prices of BHP Billiton, Rio Tinto and Fortescue all rose, but they then came back. BHP shares peaked at $37.76 and then eased to trade about $37.34 at near 11.30am, up a whole 24 cents.

Most banking and industrial shares were weaker because of the poor data from the US and the lack of any strength in the American market.

Settlement of the tax dispute helped take Asian markets higher (Tokyo briefly rose), but those gains were lost as investors lost heart from the poor night in the US. So when reading of the market reaction, remember it was like an April snow, briefly rewarding, but in the end a tease. There are far more serious matters undermining confidence in the market.

Just wait for the big miners to start bleating about lower prices, even after the favourable impact of the fall in the Australian dollar is taken into account. Wait especially for an acknowledgment that the surge in iron ore and coal prices is coming to an end.

Prices will still be up on a year ago, but all those misty-eyed projections from analysts and some investors about the China surge (or the Mining boom Market 2, as Wayne Swan calls) going on and one, will be forgotten as reality sets in, just as it set in about late April-early May when prices started easing and kept falling.