* Spot gold rallies above $1,000, highest since March 2008
* Technical momentum, options activity drive buyers
* Analysts question sustainability of the rally (Recasts, updates prices, market activity to close; adds second byline, dateline, previous LONDON)
By Frank Tang and Humeyra Pamuk
NEW YORK/LONDON, Sept 8 (Reuters) - Gold surged past $1,000 per ounce on Tuesday on pent-up technical momentum and dollar weakness, but ultimately closed shy of the key psychological barrier, although it was slightly higher than Friday's close.
Some analysts said they believed the precious metal would finally break through last year's record high at $1,030.80, but others warned that the $1,000 level was not sustainable.
Spot gold <XAU=> rose to $1,007.45 an ounce, its highest price since March 2008, when bullion touched the $1,030.80 record. It was trading at $995.80 an ounce at 3:09 p.m. EDT (1909 GMT), versus $993.85 an ounce late in New York on Monday.
U.S. December gold futures <GCZ9> settled up $3.10 at $999.80 an ounce on the COMEX division of the New York Mercantile Exchange, versus Friday's close at $996.70 an ounce before the U.S. long weekend.
"Gold's probably the most technically traded financial instrument in the world," analyst David Thurtell at Citigroup in London.
"Where can it go? If it closes through $1,010 and plus tonight, you'd have to think there would be a lot of very nervous shorts around that are getting close to covering, and then it really could pop and go up another $50 quite quickly," he said.
Brian Hicks, a portfolio manager at Texas-based U.S. Global Investors, which manages more than $2 billion mutual fund assets, said gold rallied in advance of a sharp decline of the dollar due to a rosy economic outlook.
"Gold is hitting $1,000 mainly due to the breakdown in the dollar today," Hicks said. He also cited stronger commodities and rising inflation expectations amid improving economic sentiment.
For a technical story on gold, see [
] and for a snap analysis on gold's price prospects, see [ ]Other analysts questioned the sustainability of the precious metal's rally above $1,000 an ounce, which also helped boost palladium and silver to 2009 highs.
UBS analyst John Reade said in a note to clients that gold options had moved sharply after breaking through $1,000.
"Today's move in implied volatility suggests ... that a scramble for upside gold options could lead the spot gold price higher," he said.
"We are unconvinced that all the ingredients are in place for a sustained surge higher in gold," he added.
Implied volatility is a measure of demand for options, which investors use to take advantage of, or protect themselves against, sharp movements in spot rates.
Spot gold has made three attempts to rise and stay above $1,000. The market stayed above the key level for one day in February and three days in record-setting March 2008.
SUSTAINABLE?
The $1,000 an ounce level is far from an inflation-adjusted record for gold. Analysts at GFMS put that as high as $2,079 per ounce.
Some analysts have said the higher gold price reflects uncertainty across markets about how central banks will untangle themselves from fiscal stimulus aimed at reviving economic growth, as well as dollar weakness.
"Gold is celebrating because the day when inflation might return is getting sooner rather than later," Ashok Shah, chief investment officer at London and Capital.
"As long as the authorities are intent on not reversing their policies, then gold will remain in demand and it will be wanted," Shah said.
In other metals, silver <XAG=> hit a 13-month high of $16.81 an ounce and was at $16.42 an ounce versus $16.29 an ounce. Palladium <XPD=> touched $296.50 an ounce, its highest since September last year. It was last at $293 an ounce versus Monday's finish of $291.50.
Platinum <XPT=> was at $1,285 an ounce versus $1,255.00 an ounce on Monday.
For a graphic on gold futures versus the S&P index click on: http://graphics.thomsonreuters.com/099/CMD_GLDSP0909.gif
Close Change Pct 2008 YTD
Chg Close Pct Chg US gold <GCZ9> 999.80 3.10 0.3 884.30 13.1 US silver <SIZ9> 16.510 0.225 1.4 11.295 46.2 US platinum <PLV9> 1289.60 30.50 2.4 941.50 37.0 US palladium <PAZ9> 298.60 2.60 0.9 188.70 58.2 Prices at 3:09 p.m. EDT (1909 GMT) Gold <XAU=> 996.15 2.30 0.2 878.200 13.4 Silver <XAG=> 16.43 0.14 0.9 11.30 45.4 Platinum <XPT=> 1285.00 30.00 2.4 924.50 39.0 Palladium <XPD=> 293.00 1.50 0.5 184.50 58.8 Gold Fix <XAUFIX=> 1000.75 7.75 0.8 836.50 19.6 Silver Fix <XAGFIX=> 16.750 0.540 3.3 14.760 13.5 Platinum Fix <XPTFIX=> 1280.00 0.00 0.0 1529.00 -16.3 Palladium Fix <XPDFIX=> 296.00 0.00 0.0 365.00 -18.9 (Additional reporting by Veronica Brown in London and Chikako Mogi in Tokyo; Editing by Lisa Shumaker)