Milan Radisics / Crystallised patterns in an abandoned pond used for the disposal and stacking of phosphogypsum with shallow, but highly toxic radioactive green water in Huelva, Southern Spain. Phosphogypsum is a radi...

Milan Radisics / Service road crossing an abandoned pond used for the disposal and stacking of phosphogypsum with crystallised patterns and shallow, but highly toxic radioactive green water in Huelva, Southern Spain....

Milan Radisics / Service road crossing an abandoned pond used for the disposal and stacking of phosphogypsum with crystallised patterns and shallow, but highly toxic radioactive green water in Huelva, Southern Spain....

Floris van Breugel / Black and white photograph of Ice crystals up to 12 inches long along a small creek in a remote valley, Brooks Range, Gates of the Arctic National Park, Alaska, August 2014.

Franco Banfi / Nudibranch (Janolus cristatus) Vela Luka, Korcula Island, Croatia, Adriatic Sea, Mediterranean

Franco Banfi,Franco Banfi / Ocean Sunfish (Mola Mola) with Longfinned bannerfish (Heniochus acuminatus) Crystal Bay, Nusa Penida, Bali Island, Indonesia, Pacific Ocean

Alex Mustard / Trees and sky photographed at dawn through the surface of Three Sisters Spring, Crystal River, Florida, United States of America.

Gavin Hellier / Aerial view of the famous Blue Lagoon and Belcekiz beach along the 'Turquoise' coast, Oludeniz near Fethiye, Mediterrean Coast, Turkey 2008

Gavin Hellier / Aerial view of the famous Blue Lagoon and Belcekiz beach along the 'Turquoise' coast, Oludeniz near Fethiye, Mediterrean Coast, Turkey 2008

Cheryl-Samantha Owen / Blacktip reef sharks (Carcharhinus melanopterus) swimming in shallow crystal clear water, Aldabra Atoll, Seychelles, Indian Ocean

Cheryl-Samantha Owen / Blacktip reef sharks (Carcharhinus melanopterus) swimming in shallow crystal clear water, Aldabra Atoll, Seychelles, Indian Ocean

Alex Mustard / Young Florida manatee (Trichechus manatus latirostrus) portrait, Three Sisters Spring, Crystal River, Florida, USA. February 2010

Alex Mustard / Florida manatee (Trichechus manatus latirostrus) being cleaned by blue gill sunfish (Lepomis macrochirus). Three Sisters Spring, Crystal River, Florida. USA. February 2010

Alex Mustard / RF- Florida manatee (Trichechus manatus latirostrus) portrait in Three Sisters Spring. Crystal River, Florida, USA. February 2010. (This image may be licensed either as rights managed or royalty free....

Alex Mustard / A adult Florida manatee (Trichechus manatus latirostrus) stays warm in a freshwater spring in winter. Three Sisters Spring, Crystal River, Florida. USA. February 2010

Alex Mustard / A Florida manatee (Trichechus manatus latirostrus) head portrait in Three Sisters Spring. Crystal River, Florida, USA. February 2010

Alex Mustard / A group of Florida manatees (Trichechus manatus latirostrus) sleeping in the afternoon at Three Sisters Spring. Crystal River, Florida, USA. Manatees sleep on the bottom of the spring, floating up per...

Alex Mustard / A group of Florida manatees (Trichechus manatus latirostrus) sleeping in the afternoon at Three Sisters Spring. Manatees sleep on the bottom of this shallow spring, occasionally rising to the surface...

Alex Mustard / A Florida manatee (Trichechus manatus latirostrus) close up head /nostrils portrait in Three Sisters Spring. Crystal River, Florida, USA. February 2010

Alex Mustard / Two Florida manatee (Trichechus manatus latirostrus) surfacing to breathe, in morning light. Three Sisters Spring, Crystal River, Florida. USA. January

Alex Mustard / Bluegill sunfish (Lepomis macrochirus) sheltering beneath a Florida manatee (Trichechus manatus latirostrus). Crystal River, Florida, USA.

Alex Mustard / Young Florida manatee (Trichechus manatus latirostrus) stays warm in a freshwater spring in winter, at dawn. Three Sisters Spring, Crystal River, Florida, USA. January

Alex Mustard / Florida manatee (Trichechus manatus latirostrus) swimming under trees in Three Sisters Spring, Crystal River, Florida, USA. January

David Fleetham / Florida manatee (Trichechus manatus latirostris) at Three Sisters Spring in Crystal River, Florida, USA.

Onne van der Wal / Crystal clear shallows under a blue sky. Exumas, Bahamas, Caribbean, June 2009.

David Fleetham / Florida Manatee (Trichechus manatus latirostris), Three Sisters Spring, Crystal River, Florida, USA. National Wildlife Federation Photo Contest Grand Prize WINNER 2010.

Wild Wonders of Europe / Biancarelli / Chub (Leuciscus cephalus) swimming in crystal clear water, Plitvice National Park, Croatia, October 2008

Michael Pitts / Aerial view of cruise ship, M/V Crystal Symphony, passing through the Panama canal, heading towards Mira Flores Locks, Panama 2005 2006

Ingo Arndt / Sea ice crystals. Fine piece of an ice core collected on an ice floe photographed under polarized light. Crystals grown under calm water conditions. Horizontal section. Weddell Sea, Antarctica FOR SAL...

Doug Perrine / Florida manatee portrait {Trichchus manatus latirostris} Crystal River, Florida, USA (Non-ex).

Norbert Wu / West Indian Manatee (Trichechus manatus), Crystal River, Florida

Jim Brandenburg / Ice crystals, Lake Superior, Michigan

Yva Momatiuk & John Eastcott / Ripples on white gypsum sand dunes, White Sands National Park, New Mexico

Tim Fitzharris / West Indian Manatee (Trichechus manatus) mother and calf, Crystal River, Florida

Hiroya Minakuchi / Crystal Jellyfish (Aequorea aequorea), North Pacific Ocean

Fred Bavendam / West Indian Manatee (Trichechus manatus) named Sadie has propeller cuts on the tail, but her calf remains intact, every year boats kill dozens of manatees, Kings Bay, Crystal River, Florida

Fred Bavendam / West Indian Manatee (Trichechus manatus) mother and calf nuzzling, Kings Bay, Crystal River, Florida

Franco Banfi / Crystal prawn (Periclimenes scriptus) inside a Sand anemone (Condylactis aurantiaca) Ponza island, Italy, Tyrrhenian Sea, Mediterranean.

Guy Edwardes / Coral slime mould (Ceratiomyxa fruticulosa) sporangia with ice crystal appearance, on decaying log. New Forest National Park, England, UK. October. Focus stacked image.

Ashley Cooper / Ice patterns in frozen puddle on summit of Ingleborough, people walking dogs in background. Yorkshire Dales National Park, England, UK. December 2019.

Ashley Cooper / Snow covered mountains at edge of Lallemand Fjord, until recently large parts of the fjord were covered by the Muller ice shelf which collapsed due to climate change. Crystal Sound, Antarctic Peninsul...

Ashley Cooper / Snow covered mountains at edge of Lallemand Fjord, until recently large parts of the fjord were covered by the Muller ice shelf which collapsed due to climate change. Crystal Sound, Antarctic Peninsul...

Linda Pitkin / Hedge woundwort (Stachys sylvatica) Crystal Palace Park, Kent, England, July.

Linda Pitkin / Greater duckweed (Spirodela polyrhiza), in pond. Crystal Palace Park, Kent, England, July.

Linda Pitkin / Yellow loosestrife (Lysimachia vulgaris) Crystal Palace Park, Kent, England, July.

John Cancalosi / Orbicular jasper (cryptocrystalline quartz), also known as 'Ocean Jasper', Madagascar

John Cancalosi / Crystals of Sphalerite (dark colour), Pyrite (golden colour) and Quartz (white colour), Peru

John Cancalosi / Native Gold on Quartz, Nevada, USA