At noon AEST on Tuesday, the benchmark S&P/ASX200 index was up 26.9 points, or 0.35 per cent, to 7,676.1, while the broader All Ordinaries had gained 26.7 points, or 0.34 per cent, to 7,928.7.
"Investors re-engaged with risky assets overnight as risk sentiment improved amid an environment of easing tensions in the Middle East and a lack of top-tier economic data," wrote St George economist Jarek Kowcza.
Gold, which has been rallying since the start of March to hit multiple new all-time highs, dropped by $US17 to a two-week low of $2,309 an ounce overnight as the threat of war in the Middle East receded.
Northern Star was down 4.7 per cent, Newmont had dropped 4.1 per cent and Evolution had fallen 3.4 per cent.
Elsewhere in the materials sector, BHP and Fortescue were up 0.1 per cent while Rio Tinto was flat. Overall the mining sector was down 0.3 per cent, joining energy and industrials as modest losers.
The ASX's eight other sectors had gained ground, with health care and property the best performers, up 1.2 per cent.
Private hospital operator Ramsay Health Care had gained 3.7 per cent, while shopping centre owners GPT and Scentre Group were both up 1.8 per cent.
In the energy sector, oil and gas producers were modest gainers but coalminers and uranium developers had lost ground.
Woodside had climbed 0.3 per cent, while coalminers Whitehaven, Yancoal and New Hope Corporation and yellowcake plays Boss Energy and Paladin Energy were all down between 2.1 and 2.7 per cent.
The Big Four banks were all higher, with ANZ adding 0.7 per cent, Westpac and NAB climbing 0.9 per cent and CBA up by 1.0 per cent.
Lifestyle Communities was the biggest loser in the ASX200, falling 11.7 per cent to $12.58 after the retirement village developer said its beachside and northwest Melbourne sales had been lagging expectations, because customers were taking longer selling their existing homes than forecast.
Brambles was down 5.7 per cent to $14.745 after a softer-than-expected third-quarter sales update from the reusable pallet company.
"Despite ... improved supply chain dynamics, we continue to experience inflationary pressures in labour costs globally, transport costs in Europe and ongoing fluctuations in fuel prices," said chief executive Graham Chipchase.
Also on Tuesday, a biannual survey by global trading platform IG found 65 per cent of its clients believed the ASX 200 would rise in the next six months, the most bullish results since January 2022. Confidence in the ASX200 has been steadily increasing over the last 18 months, the survey indicated.
The Australian dollar was buying 64.63 US cents, from 64.33 US cents at Monday's ASX close.