Montana Bourke is the kind of woman who throws on diamonds the way most throw on denim — effortlessly, instinctively, and with a touch of rebellion. For her, luxury isn’t about velvet boxes or loud logos; it’s that lived-in sparkle that catches the light when she’s sipping her morning coffee. It’s this cool, undone energy that pulses through Carat Cake Jewellery — Montana’s Sydney-born label that’s quietly rewriting the fine-jewellery rulebook with pieces that are equal parts unpretentious and irresistible.

Now eight years in, Carat Cake has become the insiders’ favourite for lab-grown and natural diamonds, bespoke engagement rings, and those everyday “I-just-threw-this-on” pieces that make you look — and feel — expensive. “Fine jewellery should be fun, not formal,” Montana says. “It’s about celebrating life’s moments, big or small, and creating pieces that make you feel good.”

But if you’re expecting a conventional jeweller with a gemology degree and a family history of goldsmithing, think again. Montana is entirely self-taught. A working mother of two and self-proclaimed “Type B” personality, she laughs that she thrives in the chaos — “throw five balls and I’ll juggle them all.”

What began back in 2018 as a side hustle — a curious experiment rather than a grand plan — has since evolved into a multi-six-figure brand — one that’s as grounded as it is glittering. “Honestly, I didn’t even know if the business would last this long,” Montana admits. “At first, I just wanted to make a sale a week — maybe a month. For the first two or three years, I was barely even profitable.”

Then came the pandemic — and a plot twist. Pregnant with her first child and armed with a little extra time (and a lot of drive), Montana decided to bet on herself. “That’s when I started treating Carat Cake like a business, not just a creative outlet,” she says. She invested in stock, focused on transparency, and built a brand rooted in honesty and accessibility. “I was happy to make $500 on a piece if it meant building trust,” she explains. “Luxury shouldn’t feel out of reach or out of touch.”

Today, that same transparency makes up Carat Cake’s DNA. Prices are listed openly online, consultations happen digitally or from Montana’s by-appointment studio at One Sydney Harbour, and every client gets her direct attention. “I wanted people to know exactly what they were paying for,” she says. “The jewellery industry has always been so secretive. I wanted to flip that.”

And flip it, she did. This September, from a trunk-show in Hong Kong, Carat Cake sold over $120,000 in loose lab-grown and coloured diamonds — in just 48 hours, all via Instagram DMs. The record-breaking sale marked a turning point, not just for Montana, but for Australia’s fine jewellery landscape. “Live-selling is huge overseas, but still pretty new here,” she explains. “It worked because my clients already trusted me — They’ve seen me show up online every day, explaining the process, sharing behind-the-scenes, and giving honest advice. That trust made it possible.”

Behind the polished Instagram feed is a designer with serious range. Montana personally oversees production across her Sydney and Hong Kong workshops — Sydney handling engagement rings and pieces that require a personal touch, and Hong Kong producing intricate tennis bracelets and necklaces. “Australia has the best jewellers in the world,” she says. “We pay for quality, and it shows. But I’m also proud that our overseas workshops are ethical and well-compensated. Nothing about Carat Cake is about cutting corners.”

Montana isn’t one to sugarcoat — especially when it comes to the industry’s most enduring myths. “Jewellery isn’t an investment,” she says, matter-of-factly. “It’s like a car — it loses value the second you buy it. You wouldn’t shop for a pair of heels hoping they’ll go up in value, so why would you with a ring?”

It’s that refreshing honesty that’s become her signature. Rather than pushing trends or sales, Montana empowers her clients to make decisions that feel right — not just look right. “I’m not pro-lab or pro-natural,” she explains. “I’m pro-informed choice. People deserve facts, not fluff.”

Many jewellers still hide behind glossy marketing and smoke-and-mirror language — but Montana isn’t here for that. “There’s so much misinformation out there,” she says. “Once you actually learn the difference, you stop chasing what’s ‘better’’ and start choosing what’s better for you — your taste, your values, your budget.”

This commitment honesty is Montana’s superpower. “I’ll always be completely truthful with my clients — I’ll never tell someone something just to make a sale” she admits. “My job is to help people make smart, confident choices, not to convince them. That honesty has built real trust — and I think that’s what keeps people coming back.”

Through it all, Montana keeps her feet firmly on the ground. “I’m just a mum trying to build something beautiful and honest,” she says. “I want women to feel good in what they buy — to wear their jewellery without waiting for an occasion.”

Carat Cake Jewellery, at its heart, is about that duality: polish with play, elegance without ego. Or, as Montana likes to say, “luxury that doesn’t take itself too seriously.”