with your mouse to see the details. 
Date
- This usually corresponds to the date of the analysis. In the case of a duplicate report, this date reflects when it was issued, not the date of testing.
ID Number
- This is the identification number of your report. It is also a means of establishing whether or not the report is authentic. When communicating with us on an existing report, we need this number to track down its details.
Species
- The mineral name of a gem that is based on its chemical composition and crystal structure.
Variety
- Varieties are types of gems which belong to the same species but which exhibit a different colour, typically due to the presence of small amounts of trace elements.
Weight
- In order to ascertain the exact weight of a gemstone or item of jewellery, we use a highly accurate scale. The unit of measurement used for the weight of a gemstone is a carat. One carat is equal to one fifth of a gram, i.e. 0.2 grams. The measurement in carats is given to two decimal places.
Measurements
- A micrometer is used to measure accurately the dimensions of a gemstone. The measurement unit we use is millimetres; each measurement is given to two decimal places.
Shape
- Gemstones are most commonly cut into round, oval, cushion, pear, octagonal and heart shapes. There is a wide variety of standard shapes, each of which may also be modified to the extent that they can become fancy shapes.
Color
- Gemstones come in all kinds of colour.
Transparency
- Transparency describes the amount of light able to pass through the gemstone. We use the following terms to describe the different grades of transparency:
1.Transparent: the stone is completely transparent – you can see all the way through and can read a text through it.
2.Semi-transparent: there is slight haze in the stone, you cannot see clearly through. Reading text through the stone is almost impossible.
3.Translucent: some light passes through the stone, but it is difficult to see through it.
4.Semi-translucent: a tiny amount of light passes through the stone.
5.Opaque: no light manages to pass through the stone at all.
Treatment
- This is where we report on whether and how a gemstone is treated, or if the colour is natural.
Origin
- On request, the BIG Lab can express an opinion on the probable geographic origin of a gemstone. This opinion is based on comparisons of the stone’s internal characteristics and physical and chemical properties with the characteristics of reference stones from a known origin. It is not always possible to determine an origin; in some cases, the available information is insufficient or ambiguous, in which event we do not comment on the origin.
Hardness
- The Mohs scale (from 1 to 10) of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material.
Comments
- Here we describe other identifying characteristics of the diamond that was not mentioned otherwise in the report.
Photographic Illustration
- Each of our Gemstone Reports comes with a photograph taken by our photographer in the laboratory. The high-resolution photos are true to scale and approximately true to colour.