Pseudomorphs In Nephrite – A Preliminary Microscopic Study
Black Wyoming ‘Newer’ Quartz Pseudomorphing Next To Old Frog Skin Morphs
Lacking the sophisticated millions of dollars-worth of equipment of a lab, such as the GIA, field amateurs must often do their best with the tools at hand and the observation skills given, and acquired, after years of research and a undying fondness for the quirks we find in nephrite jade from the different-source materials we acquire. My main study in jade has always resided in archaic manufacture and design, with an interest in the archaistic copies and refinements in techniques, and subsequent interference during time periods of upheaval, due mostly to warring and aggression along with the re-emergence of excellence during times of relative peace and stability. In the course of these studies, I have run into some of the most amazing new artists, and the raw material with which they choose to make these fabulous new creations, in what has been an approximate 10,000 year history of using the “Stone of Heaven” to create the most wonderful and enduring works of spirituality and beauty, which during approximately the Holocene Period had been used mostly for axes, celts, and hoes.
Wyoming Nephrite With Pseudomorphs In Various Stages Of Development
With this in mind, I first got interested in pseudomorphs found in nephrite jade while viewing some clear, fully transferred specimens in finished works of art during the First Annual Jade Art Now Show in 2007. This set my mind in gear as Peter Shilling and I discussed the matter, and he explained the currently-accepted general theory of their occurrence. The current thought process at the time was that Quartz crystals that had either been totally absorbed by the nephrite formation, or had adhered to the nephrite on its rise from the depths of the earth, had been dissolved or degraded over the millenia and had been replaced in its natural crystal structure by forces that had caused the nephrite to “fill in” the void left behind. Under microscopic analysis of some of these pseudomorphs, we began to see some anomalies in this theory and wanted to find some more examples to examine. Mr Warren Rees, G. G., who was attending the first annual Jade Art Now Show, noticed my curiosity and in his delightful Southern-Gentleman way, made it a point to bring me many samples from his years of hunting, cutting and carving Wyoming Nephrite specimens over the years. Peter Shilling and Warren both brought multiple specimens to the second annual Jade Art Now Show in 2008 (and I had collected a few specimens during the year), for all of us to further examine with the naked eye and under microscopic conditions. This gathering of specimens and investigation was also furthered by us and other artists, during the Third Annual Jade Art Now Show in 2009.
Wyoming Black Nephrite With Quartz Pseudomorphing to ‘Frog Skin’
- Black Wyoming Pseudomorph In The Process of Exchanging Ions
Photo Taken with Canon EOS XSi Under 25X Microscopic Power
By the end of end of the Third Annual Jade Art Now Show in 2009, we’d all had a wonderful opportunity to view different pseudomorphs in different stones and in differing stages of development. While viewing mostly specimens of Wyoming origin (which is considered the oldest nephrite jade by the Smithsonian Museum and the American Natural History Museum, being Precambrian in age), some pseudomorphs from the region of Turkanistan were also observed in a re-polished Ming Dynasty gray Nephrite Vessel along approximately one-third of its entire height. In these specimens it clearly shows that the quartz crystals do not dissolve and get replaced by the nephrite jade under pressure, but that there is a most likely a very clear form of atom-exchange that occurs during the stones’ long history, in association with the “foreign objects’ it either forms around, adheres to, or picks up in its path to the surface. Pictures will be added to this post in the coming weeks to show what we see in these formations, but perhaps the most phenomenal of all specimens (a sawn in half Black Wyoming Boulder) will have to wait for photographing as it is presently in the hands of Mr. Rees; it shows the most incredible rounded, egg -shaped formations that have “borrowed the iron’ from the true black Wyoming nephrite and created the familiar “frog skin” green inclusions, frog skin with red circles around them, small solid red pseudomorphs and incredible pieces of hard, red, botryoidal pieces on the “skin” of the Wyoming boulder itself.
David Fredericks
I see these nephrite pseudomorphs of quartz crystals frequently while working with Wyoming nephrite, and have a few observations and thoughts on the matter.
I believe that Dave’s ion transfer idea is correct, and that it meshes perfectly with the formation of nephrite in contact zones between two distinct masses of stone, each of which contibutes part of the ingredients of nephrite jade. Some Wyoming jade was formed in contact with quartz crystals which form a crust on the jade cobble, often penetrating into the jade, with evidence of complete conversion into pseudomorphs. These can be difficult to recognize unless they are in cross-section and show the hexagonal habit of their quartz “ancestors.”
Sometimes on wind-worn stones the quartz crystal have been completely worn away. Although quartz is lightly harder than nephrite, this is a perfect demontration of the incredible toughness of high quality nephrite. The quartz blows away in the Wyoming wind and the jade remains. This can result in beautifully sculpted stones which are the equivalent of Chinese lingbi scholars’ rocks.
As a carver I am always glad to see quartz crystals on the outside of a piece of Wyoming jade. Unless the crystals extend so far into the jade that little or no usable material can be recovered, the jade inside is some of the finest and hardest nephrite on the planet. Not only is the jade very fine, but the pseumorphs themselves are better jade than the surrounding jade. This is evidenced in the black and green Wyoming “frogskin” jade where the green pseudomorph spots are harder than the surrounding black jade. On a wind eroded surface of this material the green spots are raised bumps mimicing botryoidal bumps.
My first experience carving Wyoming nephrite was in 1977, with more intensive work investigation for the past sixteen years, so I’m just a beginner with this incredibly variable, complex, and rewarding material.