EP0003174A2 - Verzierungsgegenstände aus mehrfachen Elementen - Google Patents

Verzierungsgegenstände aus mehrfachen Elementen Download PDF

Info

Publication number
EP0003174A2
EP0003174A2 EP79300042A EP79300042A EP0003174A2 EP 0003174 A2 EP0003174 A2 EP 0003174A2 EP 79300042 A EP79300042 A EP 79300042A EP 79300042 A EP79300042 A EP 79300042A EP 0003174 A2 EP0003174 A2 EP 0003174A2
Authority
EP
European Patent Office
Prior art keywords
elements
pleochroic
alexandrite
display object
gem
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP79300042A
Other languages
English (en)
French (fr)
Other versions
EP0003174A3 (de
Inventor
Robert Graig Morris
Earl Wayne O'dell
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Honeywell International Inc
Original Assignee
Allied Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Allied Corp filed Critical Allied Corp
Publication of EP0003174A2 publication Critical patent/EP0003174A2/de
Publication of EP0003174A3 publication Critical patent/EP0003174A3/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A44—HABERDASHERY; JEWELLERY
    • A44C—PERSONAL ADORNMENTS, e.g. JEWELLERY; COINS
    • A44C17/00—Gems or the like
    • A44C17/002—Gems made of several cut pieces
    • A44C17/003—Doublet stones

Definitions

  • This invention relates to gem stones and other display objects and, more particularly, to multiplet gem stones, such as doublets and triplets, which incorporate pleochroic materials.
  • Some well-known gem crystals which exhibit pleo- chroism to a greater or lesser extent include alexandrite, andalusite, axinite, beryl, chrosoberyl, cordierite, emerald, epidot, kyanite, peridote, ruby, sinnalide, spodumene, tourmaline and zoisite.
  • a hard colorless cap may be used to mechanically protect a fragile but visually attractive stone such as opal.
  • pleochroic material refers to either natural or synthetic mineral, that is, a crystalline, inorganic oxide, for example, which evidences pleochroic behavior.
  • a display object comprising at least two optically oriented elements of at least one pleochroic material, said elements either fixed or disposed in continuously variable rotational configuration with respect to each other.
  • Such display objects may be used to provide a varying range of colors pleasing to the eye, the particular colors depending on the particular pleochroic materials and optical orientations selected.
  • a multi-element transparent gem stone comprising at least two optically oriented elements of at least one pleochroic material, said oriented elements being either physically rotated with respect to each other over a range of about 20° to 160° or separated by an optically active rotator plate.
  • the gem stones of the invention evidence enhanced colors and other unusual optical properties over those obtained in singlet construction.
  • the red overtones which obscure the daylight green color are substantially eliminated by rotating two alexandrite stones, which have been cut parallel to the "c" crystal plane, by, e.g., 90° to produce a clear intense blue-green color.
  • the stones are then cemented together to produce a doublet having a color pleasing to the eye.
  • triplet constructions
  • pleochroic minerals One of the most spectacular of the pleochroic minerals is alexandrite, BeAl 2 O 4 , containing chromium (Cr 3+ ) as an impurity. It is one of the few trichroic minerals, that is, exhibiting three distinct colors corresponding to the three possible polarization directions of light traveling through its orthorhombic crystal structure. These will be described here for later reference.
  • the function of the pleochroic materials is to act as spectrally selective polarizers by absorbing light of particular polarizations and in particular spectral regions in order to modify aspects of the color of the resulting gem.
  • all of the elements of the multiplet are of the same material, while in other instances, it is desirable to combine elements of different pleochroic materials in the same gem.
  • Display objects incorporating the teachings herein are also contemplated.
  • Such display objects like the gem stones of the invention, comprise at least two optically oriented elements of at least one pleochroic material.
  • the doublet and triplet constructions set forth below may be advantageously employed to produce display objects having colors pleasing to the eye.
  • the optically oriented elements of the display objects may be fixed with respect to each other in a manner similar to that described below for gem stones. For example, a simple cube comprising appropriately cut and oriented plates which are then cemented together may be fabricated.
  • the elements of the display objects may be disposed in continuously variable rotational configuration with respect to each other. For example, two single cubes comprising appropriately cut and oriented elements rotationally mounted on the same axis may be fabricated.
  • FIG. 2 shows, in cross-section, a top or crown portion 1 which is disposed in effectively permanent secured relation, as by cementing, to a lower or pavillion member 2.
  • Interface or mating surfaces 3 of parts 1 and 2 are first lapped and polished prior to cementing or otherwise bonding portions 1 and 2 together.
  • the actual gem cut may be any of the type usually employed, such as brilliant-cut, emerald-cut, and the like, or other cuts employing facets producing a stone pleasing to the eye.
  • One useful application of the present invention is the enhancement of the color change properties of the gem alexandrite.
  • the daylight green color is often obscured by red overtones, especially in thicker sections.
  • the alexandrite crystal section (natural or synthetic) to be fabricated into a facet gem is first oriented by means of visual inspection, optical methods or X-ray diffraction so that the three crystal directions, "a", "b” and "c", are known.
  • the crystal is then sawed in half parallel to the "c" crystal plane (i.e., perpendicular to the "c" direction).
  • the mating sawed surfaces are polished flat and placed in contact in their original orientation.
  • the stone, now in two pieces, is viewed in transmission in a direction perpendicular to the saw cut. One of the pieces is then rotated with respect to the other.
  • the stone is then rotated by some angle 6 so as to produce the desired degree of color change in the composite, and the two mating polished surfaces are cemented together using a suitable bonding agent.
  • a suitable bonding agent may be any transparent, colorless, strong glue, such as epoxy, Canada balsam, polymethyl methacrylate, cyanoacrylate or other satisfactory material.
  • Other agents requiring the application of heat, such as low melting point glasses or polymers, may also be used.
  • the angle 8 producing the blue-green color may range from about 20° to 160°. The most intense coloration is produced over the range of about 60° to 120°, and accordingly, such rotation angle is preferred.
  • the doublet crystal so formed is then fabricated into the desired finished form by conventional methods of lapidary art.
  • the faceting is done in such a way that the planar glue joint generally lies in the stone parallel to the table facet and at a position near the firgle of the stone.
  • the separation of the stone into two components may be made parallel to the "a" crystal plane, in which case a relative rotation of the two halves around an axis normal to the "a" plane will produce a deep pure blue color.
  • the angle of rotation again may vary from about 20° to 160°. The most intense coloration is produced over the range of about 60° to l20°, and accordingly, such rotation angle is preferred.
  • the same method is followed by separating the stone parallel to the "b" plane,' little or no color change will result from rotation, an observation which will be explained below.
  • the two components of a pleochroic doublet gem namely, the crown (the upper or top) component and the pavillion (the lower or back) component, are best made from crystals containing different levels of doping. This is because in most standard gem cuts, to which the present invention is primarily addressed, the crown section of the stone is thinner than the pavillion section and therefore requires deeper coloring to produce an optimum balanced coloring of the finished gem stone.
  • the daylight green color of alexandrite can be enhanced most effectively by using two natural or synthetic "c" axis alexandrite plates as described above, in which the upper or crown plate contains from 1 to 5 times as much chromium as the bottom plate, and the angle of relative rotation, e (measured between similar crystallographic directions in the upper and lower plates) lies between 20° and 160°.
  • the chromium concentration of the alexandrite crystals should, in general, be in the range of from about 0.005 to 1.0 atomic percent substitution of chromium for aluminum ions.
  • the preferred concentrations for gems with final dimensions of about 0.2 to 2 cm in diameter are about 0.02 to 0.2 atomic percent chromium in the pavillion element and about 0.06 to 0.6 atomic percent in the crown element. In general, the smaller stones require the higher chromium concentration to produce intense colors.
  • Natural or synthetic alexandrite doublet gem stones constructed according to the method of the present invention exhibit a strikingly pure daylight green coloration while still possessing the characteristic raspberry or columbine red color of alexandrite when illuminated by incandescent light or light from a wood fire, oil lamp or candle.
  • the method of the present invention can be used to produce natural or synthetic alexandrite gems possessing unprecedented color change properties not equalled by conventionally cut singlet stones of whatever origin or detailed chemical composition.
  • the pleochroic doublet functions can be illustrated using the alexandrite example by reference to the polarized absorption curves shown in FIG. 1 and the schematic doublet shown in FIG. 2. If one considers, for example, a "c" axis plate of alexandrite viewed in transmission parallel to the "c" direction (i.e., at right angles to the plate), the unpolarized light passing through the plate will be resolved by the crystal into two orthogonally polarized beams, one with E
  • a beam appears yellow-orange by virtue of the relatively low absorption in this spectral region combined with the peak in human visual spectral response, which occurs near the same spectral region.
  • both polarizations transmit with little absorption in the far red spectral region ( ⁇ > 0.65 ⁇ m).
  • the two beams recombine and, in thin sections, the color sensation produced is green.
  • a beam with an absorption coefficient, a, lower than that for either beam in the blue-green transmission band centered near ⁇ 0.5 ⁇ m.
  • I o the incident intensity
  • I the transmitted intensity
  • a the absorption coefficient
  • x the section thickness.
  • the ratio of green to orange light transmitted also varies exponentially with the thickness section "x”.
  • the color tint of certain varieties of aquamarine, morganite, beryl and ruby canrbe adjusted by combining them with dichroic plates of tourmaline or cordierite in doublet configurations as described above, with the rotation angle being adjusted to produce the desired color.
  • Triplet-gem stones accomplishing the effects discussed above for pleochroic doublets can bo produced using the variation of the present invention as described below.
  • This variation relies on the known optical rotatory power or optical activity of a-quartz (and certain other compounds of the same crystal structure, such as berlinite) to rotationally transform the polarization directions of light beams traveling in the pleochroic multiplet gem stone.
  • a beam of linearally polarized light traveling parallel to the "c" axis in a crystal of a-quartz will suffer a progressive rotation of its plane of polarization, depending on the distance traveled and the wavelength of the light.
  • due to the so-called rotatory dispersion light of shorter wavelength will suffer more rotation in a given path length than light of a longer wavelength.
  • the alexandrite-quartz-alexandrite triplet functions by transformation of the E
  • b beam in the other element through appropriate relative orientation of the pleochroic doublet components and the consequent absorption of light in the X 0.6-0.65 m spectral region which would otherwise be transmitted by single sections.
  • the rotatory power in this region is about 20° per mm, so the required thickness for a full 90° of rotation is about 4.5 mm.
  • thinner quartz plates 0.5 mm and up
  • the maximum thickness for a quartz plate employed in triplet gem stones is about 10 mm.
  • the preferred position of the quartz plate in the finished gem is generally near the girdle, and the chromium concentration ranges and ratios discussed above in connection with alexandrite doublets also apply.
  • An alexandrite doublet gem was constructed as follows. Two polished "c" axis plates of synthetic alexandrite, 'one containing 0.3 atomic percent chromium and the other.containing 0.1 atomic percent chromium, were cemented together using epoxy glue (formula), with a 90° relative rotation such that the "a" axis in one plate lay parallel to the "b" axis in the other plate. After allowing adequate time for the epoxy glue to cure, the composite was formed into a standard brilliant-cut gem by conventional lapidary di.amond grinding and polishing techniques.
  • the upper or crown plate containing 0.3 atomic percent Cr 3+
  • the pavillion or back plate containing 0.1 atomic percent Cr 3+
  • the glue joint in the finished gem was placed parallel to the table or top facet and at the level of the girdle or widest diameter of the gem.
  • the finished gem had a girdle diameter of 9.8 mm, a total height, from table to culet, of 6.1 mm and a weight of approximately 4 carats (0.8 g).
  • the color of the finished gem was deep green by daylight or fluorescent light and deep raspberry red when illuminated by an incandescent bulb or candlelight.
  • both the crown and pavillion elements were "c" axis synthetic alexandrite plates containing 0.05 atomic percent Cr 3+ . Both stone nad final width and length dimensions of 10 and 12 mm, respectively.
  • the "a" axis of the pavillion or bottom plate was parallel to the width dimension of the finished gem, as was the "b" axis of the crown plate.
  • the "b" axis of the pavillion element and the "a" axis of the crown element were both parallel to the width dimension, i.e., the reverse of stone A.
  • Both stones appeared raspberry red under incandescent light or candlelight and green in daylight. The daylight tint of stone A, however, was decidedly bluish-green, while that of stone B was more of a pure green.
  • the optical X direction is the polarization direction of light with the smallest index of refraction.
  • a standard emerald-cut gem stone measuring 6 x 5 mm is produced using the general procedures outlined in Example 1.
  • the crown plate is formed from the andalusite crystal with the polished surface perpendicular to the orange-appearing direction in the crystal so that the polished surface contains the optical X direction.
  • the pavillion plate is formed from the cordierite crystal in such a way that the optical X direction of the crystal again lies in the plane of the plate.
  • the plates are cemented together so that the optical X directions of both crystals lie parallel in the finished gem and along the long dimension.
  • the finished gem is a pleasing violet color by daylight illumination, which changes to red under incandescent light.
  • a quartz rotator plate is used to accomplish a part of the rotational transformation of polarizations in an alexandrite-quartz-alexandrite triplet.
  • a standard brilliant-cut gem stone is prepared as follows.
  • a crown plate of "c" axis synthetic alexandrite containing 0.15 atomic percent chromium is cemented to one side of a 2 mm thick "c" axis a-quartz plate.
  • To the other side of.the quartz plate is cemented a pavillion plate of "c" axis synthetic alexandrite containing 0.05 atomic percent chromium and oriented with its "a" axis rotated 45° from the "a” axis of the crown plate in a direction producing the characteristic color change (the direction of rotation required will depend on whether right or left-handed rotating quartz is used).
  • the composite so produced is then fabricated into a 15 mm diameter brilliant-cut gem stone, with the quartz plate parallel to the table facet and lying at a depth such that it is centered at the girdle plane.
  • the resulting gem appears the characteristic green color in daylight when viewed at right angles to the table facet, but changes to reddish-orange if rotate by a slight angle. Under incandescent illumination, there is a decided color change to the characteristic raspberry red color.

Landscapes

  • Adornments (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
EP79300042A 1978-01-18 1979-01-10 Verzierungsgegenstände aus mehrfachen Elementen Withdrawn EP0003174A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US87038678A 1978-01-18 1978-01-18
US870386 1978-01-18

Publications (2)

Publication Number Publication Date
EP0003174A2 true EP0003174A2 (de) 1979-07-25
EP0003174A3 EP0003174A3 (de) 1979-08-08

Family

ID=25355269

Family Applications (1)

Application Number Title Priority Date Filing Date
EP79300042A Withdrawn EP0003174A3 (de) 1978-01-18 1979-01-10 Verzierungsgegenstände aus mehrfachen Elementen

Country Status (2)

Country Link
EP (1) EP0003174A3 (de)
JP (1) JPS54110070A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2286760A (en) * 1994-02-17 1995-08-30 Atomic Energy Authority Uk Colouration of gemstones
CH709023A1 (de) * 2013-12-27 2015-06-30 Dr Daniel Rytz Verfahren zur Bildung eines Fensters in einer Zone eines Objektes, mit farblichem Wechsel und Objekte mit einem solchen Fenster.
EP2233028A3 (de) * 2009-03-26 2016-06-29 D. Swarovski KG Facettiert geschliffener Verbundkörper

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1377130A (en) * 1920-08-19 1921-05-03 Hashimoto Shozaburo Imitation stone and process for manufacturing
FR560188A (fr) * 1922-03-25 1923-09-29 Procédé de fabrication de brillant artificiel et autres pierres fines
US1745607A (en) * 1928-02-28 1930-02-04 D Esposito Ferdinand Composite gem
US2821114A (en) * 1952-04-16 1958-01-28 Pola Lux Ges Fur Blendschutz A Symmetrical interference polarizers
US3528261A (en) * 1968-04-12 1970-09-15 Harry S Jones Doublet gem construction
US3755025A (en) * 1972-01-17 1973-08-28 Chrom Tronics Inc Production of doublet blanks for simulated diamonds
DE2256955A1 (de) * 1972-11-21 1974-05-22 H W Brditschka Ohg Haid Schmuckstein
US3808836A (en) * 1972-11-30 1974-05-07 H Jones Doublet gem construction

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2286760A (en) * 1994-02-17 1995-08-30 Atomic Energy Authority Uk Colouration of gemstones
EP2233028A3 (de) * 2009-03-26 2016-06-29 D. Swarovski KG Facettiert geschliffener Verbundkörper
US9839265B2 (en) 2009-03-26 2017-12-12 D. Swarovski Kg Ground composite body comprising a glass body and a plastic
CH709023A1 (de) * 2013-12-27 2015-06-30 Dr Daniel Rytz Verfahren zur Bildung eines Fensters in einer Zone eines Objektes, mit farblichem Wechsel und Objekte mit einem solchen Fenster.

Also Published As

Publication number Publication date
JPS54110070A (en) 1979-08-29
EP0003174A3 (de) 1979-08-08

Similar Documents

Publication Publication Date Title
US4306427A (en) Chrysoberyl gemstones
US5723391A (en) Silicon carbide gemstones
Wood et al. The characterization of beryl and emerald by visible and infrared absorption spectroscopy
US6405562B1 (en) Cut gem, in particular cut diamond
US6745596B2 (en) Princess cut diamond
US20030188551A1 (en) High yield diamond
US4030317A (en) Simulated gemstone
US6698239B2 (en) Brilliant cut diamond
US5657646A (en) Jewel having multiple culets
WO2009094432A1 (en) Cut gemstone exhibiting excellent optical brilliance
US4262497A (en) Multi-element pleochroic genstomes
US3808836A (en) Doublet gem construction
KR102475053B1 (ko) 단결정 다이아몬드 재료, 및 그것을 포함하는 공구, 방사 온도 모니터, 및 적외 광학 부품
US6782715B2 (en) Gemstone arrangement
EP0003174A2 (de) Verzierungsgegenstände aus mehrfachen Elementen
US4308727A (en) Brilliant-cut stone
US3864939A (en) Doublet having fiber optical element for chatoyant or asterismal display
WO2004023920A2 (en) An enhanced diamond and method for making the same
US3755025A (en) Production of doublet blanks for simulated diamonds
Liu et al. Relationship between the crystallographic orientation and the ‘alexandrite effect’in synthetic alexandrite
CN108466162A (zh) 一种莫桑石、多功能莫桑石夹持装置
Davis " Contra Luz Opal:" Structure and Optical Properties
EP1694155B1 (de) Edelstein mit facetten
Brewster XIX. On new properties of light exhibited in the optical phenomena of mother of pearl, and other bodies to which the superficial structure of that substance can be communicated. By David Brewster, LL. DFRS Edin and FSA Edin. In a letter addressed to the Right Hon. Sir Joseph Banks, Bart. KBPR S
Darley et al. Natural Color Hydrogen-Rich Blue-Gray Diamond.

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): CH DE NL

AK Designated contracting states

Designated state(s): CH DE NL

17P Request for examination filed
RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: ALLIED CORPORATION

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19821103

RIN1 Information on inventor provided before grant (corrected)

Inventor name: O'DELL, EARL WAYNE

Inventor name: MORRIS, ROBERT GRAIG