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  Brighton (03) 9593 2197  |   Canterbury (03) 9830 5600


Garry Holloway

Garry Holloway –
Diamond Cut Expert


Founder, Owner and ‘CutNut’

 I graduated as a geologist and backpacked overland to London. I bought gems in Asia and taught myself to make jewellery. In 1976 I opened Precious Metals on a shoe-string budget. I changed the name to Holloway Diamonds in 2006. I couldn’t afford diamonds back then.

In 1984 I did well at the Gemmological Association of Australia’s Diamond Technology course. During the course, I invented the Ideal-Scope. Later I taught the course and was a national convenor for several years. I became a passionate diamond ‘Cut Nut’ crusader to improve the cut quality of all diamonds.

In the year 2000, I launched the US-patented Holloway Cut Adviser (HCA) – an online cut grading system. HCA has been used to grade billions of dollars worth of diamonds. GIA’s cut grading system came several years later, it’s not as strict as HCA, about 80% of GIA XXX diamonds fail. HCA has been used by the public and trade to grade the cut quality of billions of dollars of diamonds.

Sparkliologist, BSc, FGAA,
Dip Diamond Technology Reg’d Valuer 161



1985 Invented | 2001 Commercially Available

Garry Holloway designed the Ideal-Scope as a portable and affordable method to grade light leakage and the cut quality of diamonds. In 2001 he decided to mass produce and make them freely available. They are now used worldwide by industry cutters.

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1985 Invented | 2001 Commercially Available

Provides a grading light leakage and the cut quality of fancy-shaped diamonds.

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2000 Invented | 2007 Granted US patent

(HCA) rates a diamond’s cut in lay terms for its spread (how big the diamond is for its weight), light return, fire, and scintillation. A diamond with an HCA grade of excellent returns an excellent visual performance.

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Over the years I have produced a library of videos based on Diamond Education and Diamond Fun. Please use them as a reference. Enjoy!

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1985, Garry Holloway was a recipient of the Gemmological Association of Australia, The Sutherland Medal (now known as the Sutherland Diamond Award). Garry received this for his exceptional study results in practical diamond grading and advanced diamond grading. The award is an annual Federal recognition presented by the association.

Who’s the ‘Cut Nut’?

I was born an inventor; drove mum mad with questions. Invention came easily. I would be a billionaire if I could implement stuff.

In 1976 when I started out I began researching and invented cut grading tools. A few years later, when I met Martin Rapaport in NYC (diamond guru and economist), he started calling me ‘Cut Nut’, now my AKA.

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