Renewable and pumped hydro-focussed Genex Energy is the other.
Other new entrants to the list include several lithium exploration companies, tech stocks, a uranium exploration company and a Tasmania-based whiskey distillery.
The index measures the performance of the microcap segment of the Australian Securities Exchange.
"With 452 constituents, the index represents approximately 1% of the free float-adjusted market capitalization in Australia," MSCI said.
Energy makes up 6.78% of its index and materials takes the largest share at 29.69%, followed by healthcare at 13.65%.
"The index is reviewed quarterly—in February, May, August and November—with the objective of reflecting change in the underlying equity markets in a timely manner, while limiting undue index turnover," it said.
"During the May and November semi-annual index reviews, the index is rebalanced and the micro capitalization cutoff points are recalculated." .
Performance of the sector over 2019 and 2020 was strong at 25.44% growth and 14.71%, respectively.
"It is always pleasing for a growing company to be added to a new market index, with the resultant promise of greater international exposure, liquidity and generally broader investor interest," managing director Neil Young said.
Elixir has a large and loyal group of retail shareholders who recently threw in A$16.6 million to its share purchase plan which ran up to $20 million or double what it had raised from an oversubscribed share placement.
It is focussed on proving up its CSG in Mongolia's South Gobi desert where it has 7 million under a PSC arrangement with the government and the nation's first CSG PSC.