Old European cut is a diamond cutting method that appeared in the 19th century, developed from the old mine cut. Old mine cut is the earliest modern diamond cutting method, appeared in the 17th century, it has 58 facets, but the outline is irregular, the table is large, the crown is low, the pavilion is shallow. With the progress of technology and the in-depth study of the optical properties of diamonds, diamond cutters began to improve the old mine cut, making it closer to the ideal proportion and symmetry. They reduced the table, increased the crown height and pavilion depth, and made the outline more rounded. This formed the old European cut, which is considered to be an important milestone in diamond cutting technology. Old European cut was very popular from the late 19th century to the early 20th century, until it was replaced by modern round brilliant in the 1930s. Modern round brilliant is the result of further optimization of old European cut, it has a smaller table, higher crown height and pavilion depth, more precise symmetry and polishing quality. The characteristics of old European cut

Old European cut has the following main characteristics:

- It has 58 facets, including 32 crown facets and 24 pavilion facets (sometimes there is an extra culet facet on the pavilion).
- The outline is close to circular, but not completely round, sometimes it shows octagonal or polygonal shape.
- The table is small, accounting for about 40% of the diameter.
- The crown height is high, accounting for about 15% of the diameter.
- The pavilion depth is deep, accounting for about 40% of the diameter.
- The crown angle is large, about 35 degrees.
- The pavilion angle is small, about 40 degrees.
- The girdle is thick.
- The facet edges are not very sharp, sometimes they show slightly curved or wavy shape.
- The facet size is not very uniform, sometimes they show asymmetry or non-parallelism.
- The polishing quality is general, sometimes there are polishing marks or other surface defects.

The advantages of old European cut

Old European cut does not reach the perfect standard of modern round brilliant, but it also has its own unique charm and advantages:

- It can show the fire and brightness of diamonds, especially in dim light, it can emit a soft and charming glow. This is because old European cut has a small table and high crown
- It can show the body color of diamonds, especially for slightly colored diamonds, old European cut can make them look warmer and softer, rather than cold and icy.
- It can show the personality of diamonds, each old European cut diamond is unique, because they are all hand-cut, no two are exactly the same. They also reflect the style and culture of an era, with historical and artistic value.
- It can show the rarity of diamonds, old European cut diamonds are not common, because they have been eliminated, many have been recut into modern round brilliant. So to have an old European cut diamond is a honor and pride.

The identification methods of old European cut mainly include:

- Observe the appearance characteristics of diamonds, such as outline, table, crown height, pavilion depth, girdle, facet edge etc., compare with modern round brilliant to see if they conform to the characteristics of old European cut.
- Use a magnifying glass or microscope to observe the facet size, symmetry, polishing quality etc., to see if they have the features of old European cut.
- Use optical instruments to observe the optical performance of diamonds, such as fire, brightness, dispersion etc., to see if they match with old European cut.
- Use professional instruments to measure the proportion parameters of diamonds, such as table percentage, crown height percentage, pavilion depth percentage