She may be working with Hollywood hot shots Christian Bale, Natalie Portman and Cate Blanchett but Aussie actress, environmental activist and the face of luxury WA jewellery label Linneys, Isabel Lucas, is keeping her feet firmly on the ground.

The 28-year-old co-stars with the Oscar-winning trio in Knight of Cups, one of the most eagerly awaited cinematic releases of 2014 from acclaimed American auteur Terrence Malick (The Tree of Life, To the Wonder).

The tightly guarded film is said to be about a man, temptations, celebrity and excess and shot in an improvised style, without a script.

“Terrence is a man of such integrity and an incredible artist . . . it was such a magical experience and I am so grateful,” the softly spoken, Los Angeles-based Lucas gushes modestly to AAA Weekend.

“And Christian taught me so much and was very generous with me. Cate seems like such a guiding light and so conscious in so many ways . . . I really admire her. And Natalie (also starring in Thor: The Dark World opposite Lucas’ former lover Chris Hemsworth) was so lovely, really kind and sweet.”

Chatting to the affable one-time Home and Away Logie winner, who shot to fame in Transformers: Revenge of the Fallen, you get a sense this is a young woman who carefully considers her words and projects.

Born in Melbourne to a Swiss mother and Australian father, Lucas enjoyed an itinerant childhood with stints in Cairns, Switzerland and Kakadu in the Northern Territory.

It is this diverse upbringing which might help explain her strong sense of environmental and cultural awareness (she made headlines in 2007 by joining activists, including American actress Hayden Panettiere and prominent surfers, in a protest against dolphin hunting in Japan).

It also led her to collaborate with Linneys on the recently shot WA campaign for its new Cote d’Azur collection valued at more than $2.5 million, and create a Kimberley-inspired bespoke piece – a South Sea Australian pearl and diamond pendant using textured 18ct rose gold – for a national online auction which launches next Friday with all proceeds going to Lucas’ chosen charity, the World Wide Fund for Nature.

“I was delighted to hear it was honouring the Kimberley region because I’ve been quite passionate about protesting against the gas hub that was proposed there and it really shocked and saddened me that it would be right in the middle of the largest humpback whale nursing and breeding ground in the world, not to mention being such a historical, sacred Aboriginal site,” she says.

“We have so much to learn from the wisdom of the people who have been here for thousands of years before us and just how important it is to care for what we have and treat it in a way that is going to be sustainable. You can’t drive a car on an empty tank; it just won’t continue. We need to let our conscience kick in and be guided by that.”

As for her burgeoning film career, Lucas is surging ahead with three other US films due for release next year – including a thriller alongside *Nick Jonas *- and an Australian production that has her tight-lipped on the details.

“I can say I’m filming the movie in December in Sydney and I’m really excited but I’m not allowed to say what it is just yet,” she says.