Gem Crystal Pegmatite Pocket Formation and Survival

Mineral specimens from gem-bearing pegmatites represent some of the most profound display pieces in both private and public collections with the finest pieces constituting natural art and investments. What some collectors and the general public may not appreciate is how uncommon single gem crystals and combination specimens containing tourmaline, aquamarine, morganite, topaz and yes, rare species such as amblygonite, herderite, beryllonite, petalite, and others actually are! When we see them on display we tend to take their beauty for granted and sometimes forget about the complex journey they have made to make it to their final destination. This journey includes the complexity of their evolution from granite melts, miarolitic cavity (pocket) formation, and the process of gem crystal growth, not to mention their survival in the Earth’s crust for many millions to sometimes over a billion years! And then there is the excitement of discovery and the fastidious extraction process which makes us appreciate how wondrous these gem crystals truly are!
Speaker Bio: Dr. Thomas Campbell has had a life-long passion for minerals which was fueled by his father, a research chemist, as well as Sandy and Gloria Ludlum of What on Earth, and they helped refine his taste in collecting fine minerals. While working on his graduate degrees at South Dakota School of Mines and Technology, he met his friend and mentor W. L. "Bill" Roberts who furthered his enthusiasm for minerals and mineralogy.

[@to-kt9og]

Jem stone hunter useful video sir

[@alexace31190]

I'm looking for more information on pegmatites in VA!

[@chrisstrobel3439]

How do they know these pegmatites are Billions of years old? What kind of empirical dating methods can prove this?

[@richarddavies7419]

Radioactive uranium and thorium minerals in the associated rocks provide the data points (daughter products vs unchanged U and Th) that are used in the calculations that yield date of the original crystallization event. Other radioactive elements often provide corroborating date information.

[@elijah8684]

ƤＲＯ𝓂Ｏ𝕤ᗰ