User talk:Lucinator

March 2013

Please do not remove content or templates from pages on Wikipedia, as you did to People's Liberation Army, without giving a valid reason for the removal in the edit summary. Your content removal does not appear constructive and has been reverted. Please make use of the sandbox if you'd like to experiment with test edits. Thank you. GotR ^Talk 02:19, 5 March 2013 (UTC)

April 2024

Please stop. If you continue to add unsourced or poorly sourced content, as you did at Tourmaline, you may be blocked from editing. - FlightTime (open channel) 23:53, 1 April 2024 (UTC)

Are you a GIA certified Gemologist? Do you have ANY credentials to make such a statement? The only source for the info that was deleted was a company website hawking their own product. I did not add anything just removed false info. If you continue to have a issue take it up with the GIA or I can have the article flagged for having misinformation. Your choice. Lucinator (talk) 22:00, 2 April 2024 (UTC)

as per the GIA guidelines

Copper-bearing gem tourmaline—recognizable by its vivid neon blue to green color—has been one of the most popular colored gemstones on the market for the nearly three decades since its debut (figures 1 and 2). It was first discovered in the state of Paraíba in northeastern Brazil in the late 1980s, and subsequently found in the neighboring state of Rio Grande do Norte (Fritsch et al., 1990; Shigley et al., 2001; Furuya, 2007). These gems became known as Paraíba tourmalines after the locality of their discovery.

While top-quality Brazilian Paraíba tourmalines tend to have more intense color, there is significant overlap in the color range for all localities. Additionally, standard gemological tests cannot definitively separate stones from these three localities. As a result, there is market demand for gemological laboratories to offer origin determination for copper-bearing tourmalines

Because standard gemological properties and microscopic observations (e.g., mineral and fluid inclusions, fracture patterns, growth tubes) are not conclusive in distinguishing geographic origin for Paraíba tourmaline, other methods must be used.

Geographic origin can be conclusively and accurately determined for the vast majority of Paraíba tourmalines based on their trace element profiles, allowing this service to be offered for Paraíba tourmaline in the gem and jewelry market, such as the fine-color Brazilian stones in figure 8. Nonetheless, there are some cases where an “inconclusive” call is warranted when the trace element profiles are ambiguous or contradictory. There are three reasons for the ambiguity:

From time to time the laboratory examines Paraíba tourmalines that do not seem to match the trace element profiles of any stones in GIA’s reference collection. Obtaining reference samples with reliable provenance that match these unknown stones is currently a priority of GIA’s field gemology department; see Vertriest et al. (2019), pp. 490–511 of this issue.

New chemical discriminators may be needed. Statistical approaches such as discriminant analysis or multivariate statistics may provide additional mechanisms to evaluate the certainty of the locality determination and reduce “inconclusive” calls.

Chemical zoning in tourmaline may complicate interpretations. Color zoning is common in cuprian tourmaline and has been studied with electron probe microanalysis and LA-ICP-MS. In these studies, trace element concentrations correlate with color in naturally zoned samples (e.g., Laurs et al., 2008; Peretti et al., 2009). It is possible that the limits of chemical zoning of Paraíba tourmaline have not been included in the original fields for localities. Ideally, potential chemical zoning should be known before conducting LA-ICP-MS analysis so that all of the compositions can be captured. In tourmaline, however, chemical zoning may not include chromophores and may not be visually recognizable.

In the early twenty-first century, similarly colored gem-quality tourmalines were discovered in Nigeria and Mozambique (figures 3 and 4; Smith et al., 2001; Abduriyim and Kitawaki, 2005). However these can be differentiated by trace elements (figure 7). As noted earlier, liddicoatite can also be found in the Paraíba tourmaline market. Katsurada and Sun (2017) reported that the origin of the copper-bearing liddicoatite was unknown at the time of publication. Subsequently the source was identified as Maraca, Mozambique (Milisenda and Müller, 2017) Lucinator (talk) 22:22, 2 April 2024 (UTC)