Aether Density

Aether density refers to a scale of aethercompression as measured by a densimeter. The following standardized grades were formalized in 378 at the Nordovest Institute:

Blue is the reference grade. It is the density produced by a triplex compressor in normal conditions.
Gold is high grade. It is produced by larger industrial compressors and replaces previous proprietary standards. For example, the Northwind Rail pipeline uses Gold 6, formerly known as Ercos C.
Emerald is anything at or above Gold 10. It is produced only in Qamar and Kota to individual specification.
Gray refers to any aether density below blue.

The text below this block contains design notes, unencyclopedic writing, or an out-of-universe perspective. It should be considered incomplete and may be contradicted later.

blue is also produced industrially, especially in kota. emerald is used for high-precision magic and also planes. a key economic thing is that even in places that produce gold/emerald, it’s cheaper to sell it and buy blue