What's the difference between lava and pumice?

Lava


Definition:

  • (n.) The melted rock ejected by a volcano from its top or fissured sides. It flows out in streams sometimes miles in length. It also issues from fissures in the earth's surface, and forms beds covering many square miles, as in the Northwestern United States.

Example Sentences:

  • (1) Compare her with Megan Draper, who is in a minidress too, but one that is several inches shorter and boasts the swirling lava-lamp prints that may have been seen in Vogue at the time.
  • (2) A 2.6-mile trail links two of the biggest, most accessible lava tubes, the lower and upper tubes.
  • (3) Even by Congolese standards, Goma has endured much in its history , from mass looting by the army to the arrival of a million Rwandan Hutu refugees, years of cross-border wars and, in 2002, a volcanic eruption that poured a tide of lava through its heart.
  • (4) As the heat drained from the city’s black streets, hewn out of lava from nearby Mount Etna , the stream of new arrivals kept coming.
  • (5) On 1 February, 17 died when Mount Sinabung in North Sumatra province spewed lava and gas.
  • (6) Half of Goma was said to be on fire - blazes which were started when the lava came in contact with gasoline stored in plastic containers in buildings and garages.
  • (7) Adult female and juvenile Mexican free-tailed bats (Tadarida brasiliensis mexicana) were collected bimonthly at Lava Cave, New Mexico from May through September.
  • (8) Jesse Lava, campaign director for Beyond Bars , a prison reform advocacy group, puts it this way: Prison doesn't cure addiction.
  • (9) Most tourists satisfy themselves with a quick drive around the crater rim, stopping for photos at the viewing points, but if you really want to smell the sulphur, feel the heat of the lava and hear the hissing of the steam vents, a bike tour is perfect.
  • (10) The investigation started as an inquiry into a money-laundering operation at a car wash, and has retained the name Lava Jato even as it mushrooms to encompass other illegal activities.
  • (11) Updated at 8.09pm GMT 8.06pm GMT Falcons 20 - Seahawks 7, 2:20 3rd quarter Gonzalez is a hill of molten lava - get off him!
  • (12) As the lava cooled and contracted, it split along joints into columns, most of which are pentagonal or hexagonal, with a few three, four, and seven-sided columns scattered throughout.
  • (13) A consideration of the island as a source of 222Rn must take into account the relatively low average flux density associated with the lava fields and accompanying thin soils.
  • (14) Till last week the lava flow was 10-mile long and covered about eight square miles.
  • (15) He said lava was still flowing into Goma (population around 400,000) and had "cut the town in half", burning a number of wooden houses.
  • (16) The arterial and venous segments of SVAs and LAVAs and an equivalent length of normal vessel were harvested at 48 hours (n = 16, 16, 16), 2 weeks (n = 12, 12, 12), and 4 weeks (n = 12, 12, 12).
  • (17) Fans of the film series can experience classic scenes at a new interactive exhibition at the London wax museum after teams of artists created models of Anakin Skywalker amid the lava of Mustafar and Han Solo in the Millennium Falcon alongside his Wookiee co-pilot Chewbacca.
  • (18) The results presented in this paper do not support the hypothesis of Nardelli, Amaldi & Lava-Sanchez that the number of ribosomal cistrons in various amphibians can always be expressed as a power of 2.
  • (19) Judge Sergio Moro – who has overseen the Lava Jato (Car Wash) investigation into bribery and kickbacks at Petrobras and other major corporations – must now assess allegations that the Workers’ party figurehead accepted 3.7m reais ($1.1m) in bribes.
  • (20) The bursting strength of suture- and laser-assisted vascular anastomosis (LAVA) was assessed using a standard rat femoral artery model.

Pumice


Definition:

  • (n.) A very light porous volcanic scoria, usually of a gray color, the pores of which are capillary and parallel, giving it a fibrous structure. It is supposed to be produced by the disengagement of watery vapor without liquid or plastic lava. It is much used, esp. in the form of powder, for smoothing and polishing. Called also pumice stone.

Example Sentences:

  • (1) A new method, not previously recommended, involving the use of a green rubber wheel followed by pumice or composite finishing paste was similarly examined and found to come closest to restoring the original, natural enamel surface.
  • (2) Radiograms of the cranium show a "pumice-stone" appearance of the dome and deformation of the sella turcica.
  • (3) This layer can be removed by thorough pumicing or by grinding.
  • (4) Also, fewer bacteria were recovered from vigorously-pumiced, molar-tooth surfaces 24 h after application of albumin compared to buffer-treated controls.
  • (5) Ragwheels and pumice samples were collected and cultured, the results of which mandate the need for infection control guidelines for the dental laboratory.
  • (6) Scanning electron micrographs, surface profile tracings, surface roughness recordings, and statistical analysis of data support the finding that the best surface finish is obtained when sandblasting, hard stone, medium abrasive disk, second sandblasting, electropolishing, hard rubber point, hard felt disk with pumice slurry, and felt disk and soft brush with polishing paste are used progressively.
  • (7) Finishing was done with wet pumice and cup, wet pumice and a brush, a grit rubber polishing point, and an aluminum oxide- coated disc.
  • (8) Method I consisted of green stone, followed in sequence by finishing bur and pastes of pumice, powdered chalk, and SnO2.
  • (9) Various abrasive materials, such as pumice, polyethylene, and aluminum oxide are widely used as adjuncts in the therapy of acne.
  • (10) Pumice and air-powder polishing gave a similar reduction of the sonic scaling roughness.
  • (11) The occlusal surface was (1) air polished for 20 seconds, (2) cleaned with pumice for 20 seconds, or (3) not cleaned.
  • (12) All patients received a subgingival scaling and pumice by a hygienist every 6 months.
  • (13) Test teeth were cleaned with pumice and 10% alcohol, air-dried, and insulated at the approximal surfaces with strips of rubber dam.
  • (14) Thus, pumicing is a necessary final step with all removal procedures studied.
  • (15) The mean CO2 output during anaesthesia in paralyzed patients can be monitored by continuous capnographic analysis of the total exhaled gases, the latter being mechanically integrated by pumice canisters.
  • (16) Food particles (wheat flour, fishmeal or yeast) were ingested approximately 3 times faster than inert particles (kaolin, pumice or synthetic cellulose).
  • (17) However, when the surface of the etched enamel was pumiced, the enamel reacquired both the shine and appearance of non-etched enamel.
  • (18) Samples of used dental laboratory pumice from the two dental laboratories were cultured for the isolation of fungi.
  • (19) A flat enamel surface was obtained with 600-grit silicon carbide paper and cleaned with a rubber cup and a water slurry of fine flour of pumice.
  • (20) The rubbing application of a hydrochloric acid-pumice mixture has been advocated for the removal of fluorotic-like areas of permanent teeth.