Line, band and peak markers

The emission lines from the selected search in the Luminescence Database window are overlaid on the spectrum plot as vertical lines, as shown below. If one reference listed multiple emission lines for the same element, they will be listed on the same line, as with the eleven Tb lines from the Crabtree 1974 reference for Cassiterite shown in the example below.

Cassiterite (SnO₂) spectrum, showing the position of several Tb emission lines reported by Crabtree (1974).

If the full width at half maximum (FWHM) for an emission lines was recorded, it will be displayed in the spectrum plot as a pair of diagonal lines surrounding the vertical line marking the position (as shown below), where the full width of the diagonal line pairs is equal to the FWHM.

Scheelite (CaWO₄) spectrum, showing the position of an broad emission peak from the WO4^[2-] ion reported by Gaft et al. (1998).
[Note: the diagonal lines denote the reported FWHM of the peak].

If an emission was recorded as a band, rather than a line, the location of the band will be displayed as two parallel horizontal lines, as shown below:

Periclase (MgO) spectrum, showing the position of an emission band due to lattice defects, reported by Vu et al. (1998).

Sorting and grouping of lines

If multiple emitters and/or references are selected in the Luminescence Database window, they will be displayed in the spectrum plot on separate rows, grouped first by emitter/charge, then by material/variant, then by reference. Depending on the number of line results returned by the search, some of these groupings may be combined to fit all results on the screen.

The ordering of line results is demonstrated in the example below, which shows the lines for Wollastonite (CaSiO₃), including three elements (Cr, Fe and Mn), two ionic charges for Mn (unspecified and 2+), three variants of wollastonite (unspecified, alpha and beta), all from four references (Gaft et al. 2005, Mariano 1978, Geake et al. 1971, and Karakus & Moor 1998.)

Wollastonite (CaSiO₃) spectrum, showing the position of several emission lines from different elements, reported by multiple references.

The grouping and ordering of the lines displayed above may be understood by considering the nested tree below. Note that the lines are separated at the first level by emitter, which is alphabetically sorted (Cr, Fe, then Mn). At the next level, the lines are separated by charge, which is also sorted (e.g. for Mn, the charge is unspecified and then “2+”). At the next level, the lines are separated by material variant, which is alphabetically sorted (e.g. for Mn with unspecified charge, the variants are unspecified, “alpha”, and “beta”). At the final level, lines are separated and sorted by reference (e.g. for Mn with 2+ charge and unspecified variant, the references are “Gaft et al. 2005”, and “Karakus and Moore 1998”).

• Emitter = “Cr”
  • Charge = “3+”
    • Material variant = unspecified
      • Reference = “Gaft et al. 2005”
• Emitter = “Fe”
  • Charge = “3+”
    • Material variant = unspecified
      • Reference = “Gaft et al. 2005”
• Emitter = “Mn”
  • Charge = unspecified
    • Material variant = unspecified
      • Reference = “Mariano 1978”
    • Material variant = “alpha”
      • Reference = “Geake et al. 1971”
    • Material variant = “beta”
      • Reference = “Geake et al. 1971”
  • Charge = “2+”
    • Material variant = unspecified
      • Reference = “Gaft et al 2005”
      • Reference = “Karakus & Moore 1998”

If the results returned for the current search are too many to be displayed by the above grouping scheme, results from different publication references are first combined. In the example below, 63 results were found for calcite, including 14 emitters, 4 charges, 4 variants, and 13 references. To fit these results in the plot window, results from different references have been combined, whilst still separating results from different elements, charges and material variants.

Calcite (CaCO₃) spectrum, showing the position of all reported emission lines.
Note that due to the large number of results, the lines from different references have been grouped together.

If the user refines the results using a secondary search for a specific emitter such as Ce, the list of results is shorter, allowing OpticalFit to again separate the results by reference (as shown below). Note that the first two rows of lines in the above figure (for Ce in “Calcite” and “Calcite (Iceland spar)”) have now been split into four lines, showing the different references.

Calcite (CaCO₃) spectrum, showing the position Ce³⁺ lines.
Note that due to the lesser number of results, the lines from different references are now shown separately.

In cases where the grouping of different references together still produces too many results, OpticalFit will group together different material variants and charges, if necessary. In the example for zircon, below, the search results are grouped only by emitter, as there were too many charges, variants and references to be displayed.

Zircon (ZrSiO₄) spectrum, showing the position of all reported emission lines.
Note that due to the colossal number of results, the lines from different charges, material variants, and references have been grouped together.

Again, refining the results using a secondary search for a specific emitter (e.g. Dy) allowed OpticalFit to again separate the results by charge, variant and reference (as shown below). Note all results have the same material variant (unspecified) and charge (3+), so results are effectively separated by reference only.

Zircon (ZrSiO₄) spectrum, showing the position Dy³⁺ lines.
Note that due to the lesser number of results, the lines from different references are now shown separately.

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