Skip to content

Idaho State Gem: Star Garnets EarthCache

Hidden : 8/8/2008
Difficulty:
1 out of 5
Terrain:
1 out of 5

Size: Size:   not chosen (not chosen)

Join now to view geocache location details. It's free!

Watch

How Geocaching Works

Please note Use of geocaching.com services is subject to the terms and conditions in our disclaimer.

Geocache Description:

STAR GARNETS: Idaho State Gem since 1967

This site is at Emerald Creek Garnet Area near Clarkia, ID and is governed by the St. Joe Ranger District. There is parking and restroom at the coordinates.


If you have time, you can pay a fee ($10 for adults) and get the experience of sifting through a stockpile of gravel for garnets. Check out their website at: www.fs.fed.us/ipnf/rec/activities.html for more information. The actual dig site is open 9 a.m. to 5 p.m. Friday through Tuesday from Memorial Day thru Labor Day. They are closed Wednesday and Thursday. You can still reach the area of the coords on those days since you do not have to mine for garnets to get this earthcache.Check out some pictures I took while we dug for garnets.

This earth cache is a tribute to quality star garnets. Although internet resources vary, it is reported that there are only two places in our whole world where star garnets are found - Idaho and India. Both locations produce 4 ray star garnets, but only Idaho has been known to produce 6 ray stars. Six ray star garnets are rare. For about every four ray garnets found, only one six ray is found. In Idaho, garnets are found adjacent to metamorphic rocks that make up the western Clearwater Range. They are mined from alluvial deposits that formed from weathering of amphibolite, mica schist, gneiss, or granite.

First let's look at garnets in general for a little background information.

DEFINITION of a garnet: Latin word meaning like a grain. It refers to the occurrence where crystals resemble grains or seeds embedded in the mix. The name garnet is thought to have come from the word, pomegranate. Garnets come from the family of minerals having similar physical and crystalline properties. The star is caused by intrusions of the mineral rutile, a composition of titanium oxide. The rutile is sometimes referred as the silk in the stone.

Garnets are known by a number of trade and variety names, most of which refer to the particular color of the garnet. Example of names includes, hessonite (a fine orange, cinnamon brown or pink), tsavorite (trade name for a fine dark green), melanite (black titanium variety of a rich green). Sound confusing yet?

Garnets can display a wide variety of colors and some garnets can exhibit color-changing qualities. Colors range from yellow-green, green, purplish red, orangey red, red, reddish orange, orange, yellow-brown, reddish brown, blackish brown, grayish black, deep red.

Garnets can be traced back to prehistoric times. Industrial use of garnets first appeared in 1878 when Henry Hudson Barton created garnet-coated sandpaper. Since then industrial purposes use more than 110,000 tons per year.

Now for the Star in a Star Garnet:

The best light to view the star formation is bright sunlight at high noon. The second best is a halogen spotlight shown one to four feet above the stones. It should be straight above the center to reflect the star. To tell a good cut of stone from a poor one, shine the light a little off center. The star will appear to be off center too.

Gems can be graded on their gem quality, star quality and color.

Gem Quality
AA....Eye clean, no fractures or blemishes, well cut.
A.....Eye clean, may have small hidden inclusions, well cut.
B.....Clean, may have inclusions or slight undercutting which do not detract from the gems overall appearance. Base may have a small wedge missing due to orienting of star.(Most Star Garnets are of this quality)
C.....Small flaws are evident. Good to begin with. Sometimes a killer star will balance out the Gem grade.
D.....Fractures and inclusions...Mainly specimen.

Star Quality
1.....All rays on star are very strong.
2.....One ray on star is slightly weaker than the others.(most are like this)
3.....One ray on star is very weak.(6-Ray only)
4.....Star is visible but is weak overall.

Color
All Garnets are a dark Purplish-Red in body color.
L.....Light color, almost Red in appearance.
M.....Medium color, Purple wine, dark in appearance.
D.....Dark color, almost Black in appearance.

Grading Example:
AA1L......Eye clean, no fractures or blemishes, well cut, All rays on star are very strong, Light color, almost Red in appearance.(the best of the best)
B2M......Clean, may have inclusions, One ray on star is slightly weaker than the others, Medium color, Purple wine, dark in appearance. (an average good quality Star Garnet)

Garnets in the rough look like this if you are lucky to find them this size.



Please respect our natural forest. Do not take any gems without paying for a permit and remember to leave the area cleaner than you found it.

To log this cache:

  1. Posting a picture is no longer allowed as a requirement as of 1/1/11 but would be appreciated. If you choose to post a picture, include some of the garnets you found or use the sign in the background.
  2. Using one of the posted pictures of star garnets, grade the garnet using the grading system above. Send it in an email to me. Don't forget to tell me which garnet you are grading. Do not post it.
  3. Name a type of rock found at the site other than garnets.
  4. And most of all - enjoy yourself and share about your trip in your log.
1 2 3

Additional Hints (No hints available.)