Denver Gem & Mineral Showcase 2017
With over 900 vendors and numerous geologic rarities, the 2017 Denver Gem and Mineral Showcase had plenty to see. Read about some highlights in…
|Is a Variety of||Feldspar|
|Colors||Red, green, yellow, and peach body colors.|
|Fracture||Conchoidal, uneven, splintery|
|Cleavage||Perfect two directions|
|Absorption Spectrum||Not diagnostic.|
|Identifying Characteristics||reddish or golden platelets with metallic luster|
|Optics||Biaxial (-). 2V = 82°.|
|Optic Sign||Biaxial -|
This material contains hematite or goethite inclusions, which reflect light in parallel orientation and create a sparkling sheen in gold to brown color shades. Sunstone may be oligoclase or labradorite in composition and is much admired as a cabochon material among hobbyists. (Labradorite with aventurescence caused by copper inclusions is known as Oregon sunstone and is described in a separate gem listing). Very fine material is not abundant and is hard to obtain.
Cabochons from Norwegian and Indian material may reach 100 carats or more. Most available material cuts smaller stones, however. This is because the rough is usually badly shattered and cracked.