This page sets out who runs this site, which names on it belong to other people, and the basis on which we use the methods behind our tools. It is written in plain language. It is not legal advice to you.
Who we are
haus1919 is a trading name of Grey & Co Pte Ltd, a company registered in Singapore. Contact details are on the Contact page.
Trademarks that belong to others
- ASET® and Angular Spectrum Evaluation Tool are trademarks of the American Gem Society. AGS® and American Gem Society® are trademarks of the American Gem Society.
- GIA® is a trademark of the Gemological Institute of America, Inc.
- IGI® is a trademark of the International Gemological Institute.
- Blue Nile® is a trademark of its owner.
- Shopify is a trademark of Shopify Inc.
These names appear on this site only to identify the organisation, instrument or publication being referred to. haus1919 and Grey & Co Pte Ltd are not affiliated with, sponsored by, endorsed by or licensed by any of them. No view on this site is an ASET® image, and we do not use the American Gem Society's instruments or software. Our view is called the Light return map and is produced by our own ray tracer.
Why we are able to use the light-return method
- The method of colouring a diamond image by the direction light arrived from is described in the peer-reviewed literature (Sasián et al., Optical Engineering, 2007; see Research & credits). Published scientific ideas may be used by anyone; what the law protects is a specific patented implementation or a trademarked name.
- The US patents that covered the ASET® device and the computer-generated map, numbers 7,372,552 and 7,382,445, were filed on 20 December 2004, granted in 2008 and assigned to the Gemological Institute of America in 2022. US utility patents run twenty years from filing. Public patent records show both as expired in 2026. Once a patent expires, its claims pass into the public domain.
- Our software was written independently. It does not contain any American Gem Society or Gemological Institute of America code, data or images.
- We do not use the name ASET® for our view, in our product listings or in our advertising. It is used on this page and on the credits page only to say what we are not and to credit the originators.
If you represent one of the organisations named above and believe any statement here is wrong, write to us at the Contact page and we will correct it.
Grading laboratories and certificates
Every stone we list has a report from the International Gemological Institute (IGI). We publish the report number so that you can check it on the laboratory's own website. Our site does not connect to any laboratory's systems. Our grade score, Pass and Fail are our own assessment of the proportions printed on the report; they are not a laboratory grade and the laboratory has not reviewed them.
Pictures and videos of stones
Every picture, map, video and chart of a diamond on this site is a computer simulation produced from the proportions printed on its certificate. It is not a photograph of the stone. Stones vary in ways a certificate does not record. Our standing statement of what the simulation can and cannot show is on the Questions and method page.
Our own work
The grading model, the ray tracer, the lighting set-ups, the Flash map and the text on this site are the work of Grey & Co Pte Ltd and are protected by copyright. You may link to any page. Please ask before copying pictures or text.
Open-source components
The site uses open-source software under the Apache 2.0, MIT and SIL Open Font licences. The components and their licences are listed on the Research & credits page.
Prices and availability
Prices are shown in US dollars unless your market selector shows otherwise. Each stone is unique; once it is sold, the listing is removed. Shipping, duties and the exchange offer are described on their own pages.