Carpathite occurrence, Cook, Skamania County, Washington, USAi

Regional Level Types
Carpathite occurrence	Mineral Occurrence Area (Uncertain)
Cook	Census-designated Place
Skamania County	County
Washington	State
USA	Country

Location:
This locality extends for about 100 metres along the northeast shoulder of Washington State Highway 14 between mileposts 55 and 56. The shoulder is two metres in maximum width, and abuts a steep and partially terraced roadcut/scree slope rising several hundred metres vertically.

Coordinates (WGS84):
The center of the collecting area is at 45.708179°N., 121.680079°E. (45.708179, -121.680079)
The western edge of the collecting area is at 45.870967°N., 121.683350°E. (45.708179, -121.693350)
The eastern edge of the collecting area is at 45.709670°N., 121.677365°E. (45.709670, -121.677365)

The upper cliff areas of the roadcut frequently shed locally vesicular boulders and cobbles of the Eocene- to Miocene-aged Columbia River Basalt Group; some may eventually come to rest on the highway shoulder. Road maintenance crews periodically move the rockfall to other clearings near the roadcut. Mineral collectors can access the specimen-bearing matrix both from these dumping grounds and from the shoulder itself. Roadside collecting is hazardous due to the high traffic speed a few feet away. Productive matrix also occurs just outside the east and west boundaries, scattered along the railroad right-of-way downhill from the listed area to the Columbia River shoreline.

All the mineral species at Cook occur as microcrystalline to one-centimetre single crystals, and/or as groups or clusters of crystals up to three centimetres in greatest dimension. SEM and XRD analyses by Dr. Joy Desor (Mineralanalytik in Germany) have confirmed the identification of questionable species.

Carpathite:
Jon Gladwell discovered the rare hydrocarbon species carpathite at this location during the summer of 2020. Here, it occurs as (1) colorless to very-pale-yellow anhedral to euhedral crystals two millimetres or less in length, (2) in groups of <0.5 millimetre anhedral grains, and (3) as <0.1 millimetre microcrystalline specks. Occasional eye-visible larger individuals appear pale-green. Carpathite crystals are found (1) in close association to quartz within relict gas vacuoles, (2) as random emplacements in otherwise empty amygdules, and (3) scattered upon basalt parting surfaces. It is hypothesized that carpathite was deposited from circulating solutions very late in the hydrothermal mineralization sequence; or it may have been transported as a vapour. The source of the required carbon, and the subsequent carpathite migration into the basalt amygdules, are unknown. Investigations of these dynamics are currently (2025) underway and will be presented in a professional paper currently in press. Carpathite is very rare at Cook.

Fluorescence:
Carpathite specimens from Cook fluoresce an intense, brilliant neon-green under both short-wave and long-wave ultraviolet light. This is in contrast to the sky-blue emission of carpathite from California, U.S.A.; neon-green is the emission color from the type locality in Ukraine and from all other worldwide carpathite occurrences.
 
Quartz:
This location is noted for colorless, transparent quartz prisms up to three centimetres in length. Scepters, reverse scepters, and a variety of unusual quartz habits and formations are also reported. Amethyst in pale to medium shades of lilac, lavender and purple occur locally as short prismatic crystals and clusters up to two centimetres in largest dimension.

Other Regions, Features and Areas containing this locality

References