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Montana vs Australian Sapphires: What's the Difference?

Oct 14, 2026

Montana and Australian sapphires are both corundum, with their fundamental differences being where they’re formed and mined. Montana sapphires come from deposits in the US state of the same name, while Australian sapphires originate from Australia. Neither origin corresponds with an exact color, and both locations produce sapphires with different hues, tones, and color patterns.

Below, we’re exploring the differences between Montana and Australian sapphires to help you find the right stone for your custom engagement ring.

Montana vs. Australian Sapphires: What to Know

Montana and Australian sapphires are fundamentally the same type of stone, just of different provenance. Sapphires mined in Montana are subject to strict U.S. regulations, while Australian sapphires are also regulated by strict environmental and labor laws.

	Montana Sapphire	Australian Sapphire
Origin	Montana, USA	Australia
Gemstone	Corundum (Sapphire)	Corundum (Sapphire)
Hardness	9 Mohs	9 Mohs
Color	Varies by individual stone	Varies by individual stone
Engagement ring suitability	Excellent	Excellent
Main reason to choose	If you want a locally sourced, American sapphire	If you want Australian provenance for your gemstone

What is a Montana Sapphire?

The term “Montana sapphire” describes the geographic provenance of a stone, rather than its particular appearance. Our Montana sapphires are sourced from Rock Creek Mine in Montana and cut in the United States, making them ideal for couples who want to incorporate a little of America into their engagement ring.

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Atlahua Emerald Cut Teal Sapphire Engagement Ring

Montana sapphires have documented US origin for couples who want to prioritize traceability with natural variation amongst individual stones, including green, teal, and blue sapphires.

What is an Australian Sapphire?

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Cosmia Round Blue Sapphire Engagement Ring

An Australian sapphire is a stone that is mined in Australia. Its origin does not strictly determine its color, and many of the sapphires from Australia often display more than one visible color, incorporating hues of blue, green, and teal. Some sapphires from Australia can be “parti sapphires”, which show distinct areas of different colors, but not all Australian sapphires will fall into this category.

At Valley Rose, our Australian sapphires are sourced from small-scale artisanal miners and businesses. You can search for Australian sapphires by using our gemstone finder when designing your bespoke engagement ring.

Create a Custom Engagement Ring with a Montana or Australian Sapphire

When you’re choosing a sapphire for your custom engagement ring, start by deciding which color you want. This step helps to narrow down your selection and makes it easier to focus on comparing the tone, saturation, and cut of your stone. You can also consider the provenance of the gemstone if traceability is important or if you have a special relationship with either Montana or Australia.

You can start designing your custom engagement ring by booking a virtual consultation or exploring our expert-curated guide to get more advice on buying a sapphire ring.