Skip to Content

Reviewer notes

Use this space to describe your geocache location, container, and how it's hidden to your reviewer. If you've made changes, tell the reviewer what changes you made. The more they know, the easier it is for them to publish your geocache. This note will not be visible to the public when your geocache is published.


Pfeiffer Purple Sand

A cache by TerryDad2 Send Message to Owner Message this owner
Hidden : 9/29/2014
2 out of 5
1.5 out of 5

Size: Size: other (other)

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


How Geocaching Works

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

Geocache Description:

Bits of manganese garnet eroded out of the surrounding hills create a purple sand on this beach. Though not all of the sand on this beach is purple, it can be found in patches on the dry dunes and in rivulets in the wave wash zone.

Access to the beach is by a 2 mile one-lane road down from PCH 36.24023 / -121.77706. Additionally, there is a $10 parking fee which, unless you park up on PCH, there is no way around. It is also a very popular beach, so on weekends you will often meet a line to get in as the attendants limit entrance when the parking lot fills, allowing only one car in for every car that leaves.

The sands on this beach are not all purple. Manganese garnet sand grains accumulate in various areas on this beach and where there are enough grains, the sand turns purple. Though sometimes the color has been described as pink or lavender depending upon the lighting. The grains of garnet have a different density than the lighter colored sand. Due to this difference in density, wind and water transport segregate the different sand grains making various concentrations of color. The concentration of purple sand increases as you walk up the beach.

The garnet sand did not come from the beach cliffs or the deep valley that Sycamore Creek currently drains as garnets are not found in the rocks drained by Sycamore Creek. Instead, the garnets were eroded out of the Santa Lucia Range (located just east of here on the other side of the highway) and transported to this beach by the Big Sur River. However, the Big Sur River no longer drains through Sycamore Canyon but instead drains cuts north and drains out through Andrew Molera State Park to the beach further north. This change in drainage occurred through a process called stream capture (another EarthCache will be developed for this).

Garnet is a generic name given to a series of minerals share a common crystal structure and a generalized chemical composition of A3B2(SiO4)3 where A can be Ca, Mg, Fe2+ or Mn2+, and B can be Al, Fe3+, Mn3+, V3+ or Cr3+. Garnets can be a wide range of colors depending upon its chemical makeup. These minerals are often formed during the metamorphosis of rock to schist or gneiss, but can also be found in igneous rocks. Garnets are usually durable, so they can also be found in sedimentary rocks after being eroded from a metamorphic or igneous rock. The garnets from this beach likely formed in the granites and gneisss of the Santa Lucia Range.

The particular form of garnet on this beach is likely spessartine Mn3Al2(SiO4)3. Spessartine is relatively dense, hard, and heavy for garnet. While most references show this type as orange, you can see it is purple here.

Logging questions:

  1. The text "GC5DXJT Pfeiffer Purple Sand" on the first line.
  2. The number of people in your group.
  3. Compare how the garnet grains accumulate on the dry sand vs. the wave wash zone?
  4. In general what size are the garnet grains?
  5. Since the source of new garnet grains is cut off, why are there still garnet grains on this beach?

The above information was compiled from the following sources:


Find more Earthcaches

Additional Hints (Decrypt)

Guvax nobhg gur uneqarff naq jrvtug bs gur tenvaf.Vf gur fbhepr ernyyl tbar, jurer qbrf gur Ovt Fhe Evire pheeragyl qrcbfvg tneargf?

Decryption Key


(letter above equals below, and vice versa)



43 Logged Visits

Found it 40     Write note 2     Publish Listing 1     

View Logbook | View the Image Gallery of 41 images

**Warning! Spoilers may be included in the descriptions or links.

Current Time:
Last Updated: on 2/13/2018 12:17:31 PM (UTC-08:00) Pacific Time (US & Canada) (8:17 PM GMT)
Rendered From:Unknown
Coordinates are in the WGS84 datum

Return to the Top of the Page