This is a natural untreated rough of beryl mined in Brazil.
Weight 15.40 cts app
Size 43 x 7 x 6 mm app
- Color is varied and includes emerald green, blue to blue-green, yellow, greenish-gold, red, colorless and pink.
- Luster is vitreous.
- Transparency: Crystals are transparent to translucent.
- Crystal System is hexagonal; 6/m 2/m 2/m
- Crystal Habits typically include the hexagonal prism with pincoid terminations. The terminations are often modified by many different pyramidal faces which can sometimes produce a rounded termination in the rough shape of a used pencil eraser.
- Cleavage is imperfect in one direction (basal).
- Fracture is conchoidal.
- Hardness is 7.5 - 8.
- Specific Gravity is approximately 2.6 - 2.9 (average)
- Streak is white.
- Other Characteristics: Faces on large crystals are often pitted, striated lengthwise and rough.
- Associated Minerals include micas, quartz, euclase, calcite, tourmalines and some feldspars.
- Notable Occurrences include Colombia and some African localities for emerald; Brazil, Russia and Pakistan for aquamarine; California, Brazil, Africa, and many other localities for other beryls.
- Best Field Indicators are crystal habit, lack of good cleavage, hardness and color.