Quartz with Tourmaline

specimen number:
2292425

location:
Bald Hornet Claim, King Co., Washington, USA

description:
A plate of colorless gemmy crystallized quartz, then wispy acicular crystals of tourmaline throughout. In good condition.

The Bald Hornet claim, situated near Mount Si in King County, Washington, lies within brecciated granodiorite of the Snoqualmie Batholith, which formed during the late Oligocene to early Miocene epochs. Hydrothermal fluids circulating through the fractured intrusive rock deposited minerals within open vugs and cavities, including quartz, stibnite, and rare forms of dravite tourmaline. Historically prospected as an iron claim, the remote and steep locality eventually became famous among mineral collectors for its exceptional mineral specimens after collectors uncovered significant crystallized pockets in the late twentieth century. The site was later acquired by the state of Washington and is now protected as part of the Mount Si Natural Resource Conservation Area, meaning it is closed to further collecting.

A Japan-law twin is a specific crystallographic twinning style where two individual quartz crystals share a common plane, growing outward at a precise angle of 84 degrees and 33 minutes. This structural twin results in a highly distinctive, flat, V-shaped or heart-shaped configuration. While single quartz crystals are incredibly common worldwide, Japan-law twins require highly specific, stable growth conditions to form, making them a scarce and highly sought-after habit for collectors. The Bald Hornet claim is recognized as one of the premier North American localities for these twins, where they are often found decorated with dark sprays of tourmaline.

Questions about this specimen?
Send an email or call us: 314-341-1811.