This is a striking "striped" calcite from the amazing amethyst deposits in Uruguay, near the border with Brazil. These are very rare compared to the plain and normal amethysts this region is so famous for. The combinations with calcite, showing multiple generations of complicated growth and intergrowth between calcite and quartz (amethyst is iron rich quartz), are considered much more desirable among mineral collectors. Each piece testifies to a complicated and long growth process where the two mineral species, calcite and quartz, underwent stages and cycles of growth that resulted in the current beautiful assemblage. These are often termed "skunks" by the miners, for their unique striped and patterned forms. They look manmade but they are entirely natural, having formed approximately 100 million years ago. This example is a rare piece featuring a giant calcite crystal centered nicely on a three-dimensional host matrix of deep purple amethyst, making for a riveting contrast of both colors and geometries. There are at least five different stages of crystal growth present. The more one looks, the more layers and patterns are discerned. Most such pieces have only moderately colored amethyst of pastel saturation, but this is strong and vivid, with crystals reaching the saturated color of grape juice. It is complete all around, viewable as a walkaround specimen in 360 degrees. This hails from the collection of Dr. Eugene "Gene" Meieran, a well-known mineral collector for over 60 years. Gene, an MIT alumnus, is a member of the National Academy of Sciences, was a former Senior Fellow at INTEL, chaired the Westinghouse Science Competition, amongst many accolades. He helped scale up microprocessors and design factories in the dawn days of the microchip, travelling the world for both work and for building his mineral collection. His childhood fascination with crystals led him into science. He has spent the last 20 years building a collection of choice, unique specimens of th

Ex Gene Meieran collection