Author: Hobart M. King, Ph.D., GIA Graduate Gemologist Colored Moonstone: Moonstone can occur in several different colors. Shown here, clockwise from top left: white moonstone cabochon measuring 16 x 12 millimeters; peach moonstone cabochon measuring 12 x 10 millimeters; gray moonstone cabochon measuring 11 x 9 millimeters; green moonstone cabochon measuring 15 x 10 millimeters.
Doubly terminated quartz crystals named for Herkimer County, New York Article by: Hobart M. King, Ph.D., RPG Herkimer Diamond Quartz Crystals Vuggy rock with drusy quartz, hydrocarbon and a nice Herkimer Diamond. Rock is 6" across. Click here for a larger image, or zoom in for detail. What are Herkimer Diamonds?
Geologists use water, dyes, stains, indicator solutions, or dilute HCl (5%) when testing rocks and minerals in the field and laboratory. A dispensing bottle is used to apply one drop of liquid when performing the tests. These bottles are not recommended for use with other types of acids, acids of higher concentrations, or for long-term storage.
Libya Bordering Countries: Algeria, Chad, Egypt, Niger, Sudan, Tunisia Regional Maps: Map of Africa, World Map Where is Libya? Libya Satellite Image Libya Information: Libya is located in northern Africa. Libya is bordered by the Mediterranean Sea, Tunisia and Algeria to the west, Niger and Chad to the south, and Egypt and Sudan to the east.
By Fred and Charlotte Ward A wonderful introduction to gemstones that exhibit some optical phenomenon, including: aventurescence, chatoyance, asterism, adularescence, iridescence, fluorescence, color change and more. Learn all about the gems that display these special effects and what is happening in the stone to produce them.
The demand for rare earth elements has grown rapidly, but their occurrence in minable deposits is limited. Article by: Hobart M. King, Ph.D., RPG Rare Earth Element Production: This chart shows a history of rare earth element production, in metric tons of rare earth oxide equivalent, between 1950 and 2017.