Snowflake obsidian: 

Found in Utah - Oregon - California - Mexico and Armenia

It is a volcanic glass which has cooled more slowly than the usual Black Obsidian which allows quartz crystals to form the snowflake patterning. 

Associated with the zodiac signs - 

Virgo, Sagittarius, and in particular Capricorn.

Chakras-

Root and Sacral 

Snowflake obsidian is said to promote a calm state of mind, which can help identify patterns in life and recognize successes and mistakes. 

9 × 3 cm

203 grams