This is a term that is defined by the International Amber Association.
That definition is:
“Modified Baltic amber (Succinite) – gemstone subjected only to thermal or high-pressure treatment, which changed its physical properties, including the degree of transparency and color, or shaped under similar conditions out of one nugget, previously cut to the required size.”
When amber is cut to a shape, it may show cracks or other faults.
Being that they cannot be used, they are put into a press. The press fuses the layers and corrects faults. The resulting shapes are Modified Baltic Amber.
Amber that also falls into this category includes amber that is roasted or put into an autoclave to improve transparency or change other characteristics. You can see pictures at this link. Polished Amber Stones
Amber that has been put through an autoclave is also called Improved Amber. It is called improved because the process fuses cracks, eliminates voids, removes bubbles and improves clarity. It is much less prone to cracking, breaking and chipping than Natural Baltic Amber.
Note that this amber is subjected to pressure. It is pressed. It is not pressed in the sense of the definition of Reconstructed (Pressed) Amber as defined by the International Amber Association. But it is subjected to pressure and is therefore pressed.
It is the processing under heat and pressure that modifies the amber and improves its characteristics. See Characteristics Of Amber
Improvement includes making the jewel more durable.
Unimproved Amber, in other words Natural Baltic Amber, is full of faults and other flaws.
It is brittle. The combination of these two characteristics makes it prone to crack and chip.
Modified amber has these cracks and flaws removed. So it is less likely to crack and chip. It is more durable.
Here are some pictures of Modified Baltic Amber . Please not that the quality and appearance of Modified Baltic Amber is such that many amber professionals cannot always distinguish it from Natural Baltic Amber.
If you would like to order such amber, contact us and give us details as to what you would like.
If you have comments, questions or need other information, please contact us.