Tides and Sea Glass - When are the best times to look for Sea Glass?

Beach in Monterey, CA

After the Storm

The first low tide after a storm would be a great time to look for sea glass.  The wind will be stronger during the storm, causing higher tides and a likelihood that debris will be washed along the shore.  Then the first low tide will provide calmer waters for you to find what the storm has produced, and more of the beach will be revealed, since the water recedes during low tide.

 

Negative Tide or Low Tide

The low tide in my area is from 4-6pm today

Consult a tide table or graph for your area to determine when the low tides occur that day. There are typically two high and two low tides per day.  It is best to hunt for sea glass during what is called negative tide, which means the tide will have receded below the average low water line. Otherwise, if you hunt during a higher tide, the tide may be covering up any sea glass that has washed on the shore. Some beaches are completely covered during a high tide and are only accessible during low tide. Also note that during high tide it may be dangerous to wade in the water.

Perigean Spring Tides

The Perigean spring tides occur when the moon is closest to the earth during a spring tide. 

• Spring tides  - occur during a new moon and full moon when the earth, moon and sun are aligned. This causes the tides to be 20% higher and occurs every two weeks. 
• Perigean tides - occur every 28 days when the moon is closest to the earth, which causes an increase in the range of tides; high tides are higher and low tides are lower.

About 3 to 4 times per year, both events occur on the same day, when the moon is closest to the earth (perigee) and there is also a full moon or new moon (spring tide), termed the "Perigean Spring Tides."  On these days, the tides will be higher than most days during the year.  These would be prime days for searching for sea glass, during the first low or negative tide after a very high tide.


Visit my Etsy store to see the jewelry I've made from my sea glass finds.


Sources:

NOAA Tide Predictions
http://www.co-ops.nos.noaa.gov/tide_predictions.shtml

Wikipedia
http://en.wikipedia.org/wiki/Perigean_spring_tide

Spring Treasury

'Springy springtime finds' by SeaglassReinvented

Peacock Feather Fabric ... EmilyRoseBloss... $10.00	Brooch delicate floral ... mollymoodesign $9.00	Polka Dot All Occasion ... TheEnnaCollect... $5.00
Gorgeous Vintage Butter... lesleyhornbeck $12.00	Easter bunny ears headb... urBunny $16.00	Set ring and earrings ... irinacarmen $26.00
Stuffed Easter Bunny Ke... DesigningImpre... $11.50	Pink Dots Bunny Bib StudioInGrid $10.00	PDF Pattern - Crochet T... SweetCrocheter... $2.50
Easter Day Eggs Garland... accessory8 $22.00	Butterflies Set of 16 N... smileywalls $18.90	Chocolate Filled Toadst... andiespecialty... $42.00
Princess Star Wand in P... AmericanBlosso... $5.00	Multicolored pastel cha... strandsofgrace $56.00	Spring Pastel felt hear... LullabyMobiles $25.00
Pastel Easter Tutu TutuDoll $19.99

Treasury tool by Red Row Studio.

Here's a Kelly Green sea glass necklace to give you luck.

Available on my Etsy store.

Sea Glass Color Rarity Chart - How rare is your sea glass and why?

You can find sea glass in a range of colors, but some colors are more difficult to find than others. To understand why certain colors are more rare than others, let's first look at how glass is made. The additives that give the glass color are often expensive or difficult to obtain.

Most glass is made of 3 materials:

• Silica (sand)
• Soda (sodium carbonate)
• Lime (calcium oxide)

90% of manufactured glass is made of silica, soda and lime, and is termed Soda-Lime Glass.


How do they make colored glass?

Metals and metal oxides are added to create a specific color in the glass.
The chart below shows what metals are used to make colored glass, as well as the sea glass rarity. Note that glass made using gold or silver was produced less often than other colors, resulting in a more rare piece of sea glass. Where does your sea glass fit on the chart?

	Glass Color	Metal or Metal oxide	Sea Glass Occurrence	Rarity
	Orange	Selenium and Cadmium Sulfide	1 in 10,000	Extremely Rare
		Silver
		Iron Oxide
	Dark Purple	Manganese Dioxide	1 in 10,000
	Purple	Nickle
	Red (ruby or cranberry)	Gold	1 in 5,000
	Orange-red	Iron Oxide
	Dark Red (opaque)	Copper
		Silver
		Selenium and Cadmium Sulfide
	Turquoise	Copper Oxide	1 in 5,000
		Copper and tin
		Cobalt with copper or iron
	Yellow	Uranium dioxide (glows under UV light)	1 in 5,000
		Silver, Chromium, Zinc, Antimony, Iron, Minium, Nickle, or Cadmium – with Sulfur
	Pink	Selenium	1 in 3,000	Rare
		Arsenic
		Manganese
	“Black Glass” (dark green or dark amber)	Iron	1 in 2,500
		Cobalt and Copper
		Cobalt and Manganese
	Teal	Cobalt and Iron	1 in 2,500
		Chromium
		Aluminum Oxide and Cobalt
	Gray	Manganese	1 in 2,000
		Nickle
	Ice Blue	Copper or Copper Oxide	1 in 2,000
	Aquamarine	Copper	1 in 1,000
	Lime	Iron	1 in 1,000
		Uranium (glows under UV)
		Chromium or Cadmium
	Lavender/Amethyst	Manganese (glows orange under UV)	1 in 1,000
		Selenium
	Citron (yellow-green)	Oxidized Chromium and Potassium	1 in 500
	Opaque white (milk glass)	Tin Oxide or Zinc	1 in 500
	Cornflower Blue	Cobalt Oxide and Iron	1 in 500
	Cobalt Blue	Cobalt Oxide and Iron	1 in 300
	Honey Amber	Cerium and Iron	1 in 200	Uncommon
		Manganese and Iron
	Soft Green	Iron	1 in 200
	Seafoam Green (light green)	Iron	1 in 100
	Seafoam Blue (light blue)	Iron and Copper	1 in 100
	Forest Green	Iron and Chromium	1 in 50
	Kelly Green	Copper and Iron	3 in 10	Common
		Chromium and Arsenic or Tin
	Root Beer Brown	Iron and Sulfur or Carbon	3 in 10
	White (clear)	Manganese or Selenium	4 in 10
		Cerium Oxide

If you notice in the chart, certain types of sea glass made with Manganese or Uranium will glow under a black light or UV light!

Brown and Kelly Green glass were typically used for beer and soda bottles, thus explaining how common those colors are in sea glass. A darker green, like Forest Green was used for wine bottles and still is. White (clear) was commonly used in soda bottles, food jars, juice bottles, and tableware. Flat pieces of white sea glass could be from tableware or windows.

The more rare colors of sea glass are most likely from decorative glass, like vases, art pieces, or tableware and explains why you do not find them as often.

Note that the rarity of sea glass can vary from location to location.

Visit my Etsy shop to see how I've reinvented my sea glass into jewelry!
Facebook
Twitter


Sources:
http://en.wikipedia.org/wiki/Glass_coloring_and_color_marking

Pure sea glass: discovering nature's vanishing gems (2004) by Richard LaMotte, Sally LaMotte Crane, Celia Pearson.