The distinct color and texture of this jade, often called calcified or 'chicken-bone' jade, was probably induced by subjecting the nephrite to very high temperature, resulting in the distinctive and attractive appearance. This may represent an attempt to imitate the opaque grey and beige patina acquired by nephrite articles excavated from ancient tombs that had been transformed during the centuries in the damp earth.
For two famous examples of chicken-bone jade from the Stevens and McReynolds Collections, see B. Stevens, The Collector's Book of Snuff Bottles, New York, 1976, pp. 114-115. nos. 365 and 382.